diff --git a/src/Jenssegers/Mongodb/Auth/DatabaseTokenRepository.php b/src/Jenssegers/Mongodb/Auth/DatabaseTokenRepository.php
index da6159f9e..515fb60af 100644
--- a/src/Jenssegers/Mongodb/Auth/DatabaseTokenRepository.php
+++ b/src/Jenssegers/Mongodb/Auth/DatabaseTokenRepository.php
@@ -27,7 +27,7 @@ protected function tokenExpired($createdAt)
             $date = $createdAt->toDateTime();
             $date->setTimezone(new DateTimeZone(date_default_timezone_get()));
             $createdAt = $date->format('Y-m-d H:i:s');
-        } elseif (is_array($createdAt) and isset($createdAt['date'])) {
+        } elseif (is_array($createdAt) && isset($createdAt['date'])) {
             $date = new DateTime($createdAt['date'], new DateTimeZone(isset($createdAt['timezone']) ? $createdAt['timezone'] : 'UTC'));
             $date->setTimezone(new DateTimeZone(date_default_timezone_get()));
             $createdAt = $date->format('Y-m-d H:i:s');
diff --git a/src/Jenssegers/Mongodb/Eloquent/Builder.php b/src/Jenssegers/Mongodb/Eloquent/Builder.php
index fff1cbdb8..358be6b50 100644
--- a/src/Jenssegers/Mongodb/Eloquent/Builder.php
+++ b/src/Jenssegers/Mongodb/Eloquent/Builder.php
@@ -188,8 +188,7 @@ public function raw($expression = null)
      */
     protected function addUpdatedAtColumn(array $values)
     {
-        if (! $this->model->usesTimestamps() ||
-            is_null($this->model->getUpdatedAtColumn())) {
+        if (! $this->model->usesTimestamps() || $this->model->getUpdatedAtColumn() === null) {
             return $values;
         }
 
diff --git a/src/Jenssegers/Mongodb/Eloquent/EmbedsRelations.php b/src/Jenssegers/Mongodb/Eloquent/EmbedsRelations.php
index 307f5e330..c073e58a1 100644
--- a/src/Jenssegers/Mongodb/Eloquent/EmbedsRelations.php
+++ b/src/Jenssegers/Mongodb/Eloquent/EmbedsRelations.php
@@ -22,17 +22,17 @@ protected function embedsMany($related, $localKey = null, $foreignKey = null, $r
         // If no relation name was given, we will use this debug backtrace to extract
         // the calling method's name and use that as the relationship name as most
         // of the time this will be what we desire to use for the relationships.
-        if (is_null($relation)) {
+        if ($relation === null) {
             list(, $caller) = debug_backtrace(false);
 
             $relation = $caller['function'];
         }
 
-        if (is_null($localKey)) {
+        if ($localKey === null) {
             $localKey = $relation;
         }
 
-        if (is_null($foreignKey)) {
+        if ($foreignKey === null) {
             $foreignKey = Str::snake(class_basename($this));
         }
 
@@ -57,17 +57,17 @@ protected function embedsOne($related, $localKey = null, $foreignKey = null, $re
         // If no relation name was given, we will use this debug backtrace to extract
         // the calling method's name and use that as the relationship name as most
         // of the time this will be what we desire to use for the relationships.
-        if (is_null($relation)) {
+        if ($relation === null) {
             list(, $caller) = debug_backtrace(false);
 
             $relation = $caller['function'];
         }
 
-        if (is_null($localKey)) {
+        if ($localKey === null) {
             $localKey = $relation;
         }
 
-        if (is_null($foreignKey)) {
+        if ($foreignKey === null) {
             $foreignKey = Str::snake(class_basename($this));
         }
 
diff --git a/src/Jenssegers/Mongodb/Eloquent/HybridRelations.php b/src/Jenssegers/Mongodb/Eloquent/HybridRelations.php
index 34b8b5788..b4af4dfc8 100644
--- a/src/Jenssegers/Mongodb/Eloquent/HybridRelations.php
+++ b/src/Jenssegers/Mongodb/Eloquent/HybridRelations.php
@@ -133,7 +133,7 @@ public function belongsTo($related, $foreignKey = null, $otherKey = null, $relat
         // If no relation name was given, we will use this debug backtrace to extract
         // the calling method's name and use that as the relationship name as most
         // of the time this will be what we desire to use for the relationships.
-        if (is_null($relation)) {
+        if ($relation === null) {
             list($current, $caller) = debug_backtrace(false, 2);
 
             $relation = $caller['function'];
@@ -147,7 +147,7 @@ public function belongsTo($related, $foreignKey = null, $otherKey = null, $relat
         // If no foreign key was supplied, we can use a backtrace to guess the proper
         // foreign key name by using the name of the relationship function, which
         // when combined with an "_id" should conventionally match the columns.
-        if (is_null($foreignKey)) {
+        if ($foreignKey === null) {
             $foreignKey = Str::snake($relation) . '_id';
         }
 
@@ -177,7 +177,7 @@ public function morphTo($name = null, $type = null, $id = null, $ownerKey = null
         // If no name is provided, we will use the backtrace to get the function name
         // since that is most likely the name of the polymorphic interface. We can
         // use that to get both the class and foreign key that will be utilized.
-        if (is_null($name)) {
+        if ($name === null) {
             list($current, $caller) = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2);
 
             $name = Str::snake($caller['function']);
@@ -188,7 +188,7 @@ public function morphTo($name = null, $type = null, $id = null, $ownerKey = null
         // If the type value is null it is probably safe to assume we're eager loading
         // the relationship. When that is the case we will pass in a dummy query as
         // there are multiple types in the morph and we can't use single queries.
-        if (is_null($class = $this->$type)) {
+        if (($class = $this->$type) === null) {
             return new MorphTo(
                 $this->newQuery(), $this, $id, null, $type, $name
             );
@@ -197,15 +197,13 @@ public function morphTo($name = null, $type = null, $id = null, $ownerKey = null
         // If we are not eager loading the relationship we will essentially treat this
         // as a belongs-to style relationship since morph-to extends that class and
         // we will pass in the appropriate values so that it behaves as expected.
-        else {
-            $class = $this->getActualClassNameForMorph($class);
+        $class = $this->getActualClassNameForMorph($class);
 
-            $instance = new $class;
+        $instance = new $class;
 
-            return new MorphTo(
-                $instance->newQuery(), $this, $id, $instance->getKeyName(), $type, $name
-            );
-        }
+        return new MorphTo(
+            $instance->newQuery(), $this, $id, $instance->getKeyName(), $type, $name
+        );
     }
 
     /**
@@ -232,7 +230,7 @@ public function belongsToMany(
         // If no relationship name was passed, we will pull backtraces to get the
         // name of the calling function. We will use that function name as the
         // title of this relation since that is a great convention to apply.
-        if (is_null($relation)) {
+        if ($relation === null) {
             $relation = $this->guessBelongsToManyRelation();
         }
 
@@ -261,7 +259,7 @@ public function belongsToMany(
         // If no table name was provided, we can guess it by concatenating the two
         // models using underscores in alphabetical order. The two model names
         // are transformed to snake case from their default CamelCase also.
-        if (is_null($collection)) {
+        if ($collection === null) {
             $collection = $instance->getTable();
         }
 
@@ -303,8 +301,8 @@ public function newEloquentBuilder($query)
     {
         if (is_subclass_of($this, \Jenssegers\Mongodb\Eloquent\Model::class)) {
             return new Builder($query);
-        } else {
-            return new EloquentBuilder($query);
         }
+
+        return new EloquentBuilder($query);
     }
 }
diff --git a/src/Jenssegers/Mongodb/Query/Builder.php b/src/Jenssegers/Mongodb/Query/Builder.php
index d5c5b8278..88dfef68a 100644
--- a/src/Jenssegers/Mongodb/Query/Builder.php
+++ b/src/Jenssegers/Mongodb/Query/Builder.php
@@ -233,7 +233,7 @@ public function getFresh($columns = [])
         // If no columns have been specified for the select statement, we will set them
         // here to either the passed columns, or the standard default of retrieving
         // all of the columns on the table using the "wildcard" column character.
-        if (is_null($this->columns)) {
+        if ($this->columns === null) {
             $this->columns = $columns;
         }
 
@@ -469,7 +469,7 @@ public function aggregate($function, $columns = [])
      */
     public function exists()
     {
-        return !is_null($this->first());
+        return $this->first() !== null;
     }
 
     /**
@@ -580,7 +580,7 @@ public function insertGetId(array $values, $sequence = null)
         $result = $this->collection->insertOne($values);
 
         if (1 == (int) $result->isAcknowledged()) {
-            if (is_null($sequence)) {
+            if ($sequence === null) {
                 $sequence = '_id';
             }
 
@@ -652,7 +652,7 @@ public function forPageAfterId($perPage = 15, $lastId = 0, $column = '_id')
      */
     public function pluck($column, $key = null)
     {
-        $results = $this->get(is_null($key) ? [$column] : [$column, $key]);
+        $results = $this->get($key === null ? [$column] : [$column, $key]);
 
         // Convert ObjectID's to strings
         if ($key == '_id') {
@@ -674,7 +674,7 @@ public function delete($id = null)
         // If an ID is passed to the method, we will set the where clause to check
         // the ID to allow developers to simply and quickly remove a single row
         // from their database without manually specifying the where clauses.
-        if (!is_null($id)) {
+        if ($id !== null) {
             $this->where('_id', '=', $id);
         }
 
@@ -730,8 +730,10 @@ public function raw($expression = null)
         // Execute the closure on the mongodb collection
         if ($expression instanceof Closure) {
             return call_user_func($expression, $this->collection);
-        } // Create an expression for the given value
-        elseif (!is_null($expression)) {
+        }
+
+        // Create an expression for the given value
+        if ($expression !== null) {
             return new Expression($expression);
         }
 
@@ -854,7 +856,9 @@ public function convertKey($id)
     {
         if (is_string($id) && strlen($id) === 24 && ctype_xdigit($id)) {
             return new ObjectID($id);
-        } elseif (is_string($id) && strlen($id) === 16 && preg_match('~[^\x20-\x7E\t\r\n]~', $id) > 0) {
+        }
+
+        if (is_string($id) && strlen($id) === 16 && preg_match('~[^\x20-\x7E\t\r\n]~', $id) > 0) {
             return new Binary($id, Binary::TYPE_UUID);
         }
 
@@ -1009,7 +1013,7 @@ protected function compileWhereBasic(array $where)
                 $regex = '^' . $regex;
             }
             if (!Str::endsWith($value, '%')) {
-                $regex = $regex . '$';
+                $regex .= '$';
             }
 
             $value = new Regex($regex, 'i');
@@ -1121,14 +1125,14 @@ protected function compileWhereBetween(array $where)
                     ],
                 ],
             ];
-        } else {
-            return [
-                $column => [
-                    '$gte' => $values[0],
-                    '$lte' => $values[1],
-                ],
-            ];
         }
+
+        return [
+            $column => [
+                '$gte' => $values[0],
+                '$lte' => $values[1],
+            ],
+        ];
     }
 
     /**
diff --git a/src/Jenssegers/Mongodb/Queue/MongoQueue.php b/src/Jenssegers/Mongodb/Queue/MongoQueue.php
index e9cd8da9c..5f08f7071 100644
--- a/src/Jenssegers/Mongodb/Queue/MongoQueue.php
+++ b/src/Jenssegers/Mongodb/Queue/MongoQueue.php
@@ -39,7 +39,7 @@ public function pop($queue = null)
     {
         $queue = $this->getQueue($queue);
 
-        if (!is_null($this->retryAfter)) {
+        if ($this->retryAfter !== null) {
             $this->releaseJobsThatHaveBeenReservedTooLong($queue);
         }
 
diff --git a/src/Jenssegers/Mongodb/Relations/EmbedsMany.php b/src/Jenssegers/Mongodb/Relations/EmbedsMany.php
index 825b0d594..e26658e69 100644
--- a/src/Jenssegers/Mongodb/Relations/EmbedsMany.php
+++ b/src/Jenssegers/Mongodb/Relations/EmbedsMany.php
@@ -130,9 +130,9 @@ public function associate(Model $model)
     {
         if (!$this->contains($model)) {
             return $this->associateNew($model);
-        } else {
-            return $this->associateExisting($model);
         }
+
+        return $this->associateExisting($model);
     }
 
     /**
diff --git a/src/Jenssegers/Mongodb/Relations/EmbedsOneOrMany.php b/src/Jenssegers/Mongodb/Relations/EmbedsOneOrMany.php
index 177160bf1..f3bc58b8e 100644
--- a/src/Jenssegers/Mongodb/Relations/EmbedsOneOrMany.php
+++ b/src/Jenssegers/Mongodb/Relations/EmbedsOneOrMany.php
@@ -279,7 +279,7 @@ protected function toCollection(array $records = [])
      */
     protected function toModel($attributes = [])
     {
-        if (is_null($attributes)) {
+        if ($attributes === null) {
             return;
         }
 
diff --git a/src/Jenssegers/Mongodb/Schema/Blueprint.php b/src/Jenssegers/Mongodb/Schema/Blueprint.php
index 0c01c96aa..4b30c87fc 100644
--- a/src/Jenssegers/Mongodb/Schema/Blueprint.php
+++ b/src/Jenssegers/Mongodb/Schema/Blueprint.php
@@ -243,7 +243,7 @@ public function sparse_and_unique($columns = null, $options = [])
      */
     protected function fluent($columns = null)
     {
-        if (is_null($columns)) {
+        if ($columns === null) {
             return $this->columns;
         } elseif (is_string($columns)) {
             return $this->columns = [$columns];
diff --git a/src/Jenssegers/Mongodb/Validation/DatabasePresenceVerifier.php b/src/Jenssegers/Mongodb/Validation/DatabasePresenceVerifier.php
index 75722a8cc..fa3d68854 100644
--- a/src/Jenssegers/Mongodb/Validation/DatabasePresenceVerifier.php
+++ b/src/Jenssegers/Mongodb/Validation/DatabasePresenceVerifier.php
@@ -19,7 +19,7 @@ public function getCount($collection, $column, $value, $excludeId = null, $idCol
     {
         $query = $this->table($collection)->where($column, 'regex', "/$value/i");
 
-        if (!is_null($excludeId) && $excludeId != 'NULL') {
+        if ($excludeId !== null && $excludeId != 'NULL') {
             $query->where($idColumn ?: 'id', '<>', $excludeId);
         }
 
diff --git a/tests/CollectionTest.php b/tests/CollectionTest.php
index f7b37bbac..d38687a54 100644
--- a/tests/CollectionTest.php
+++ b/tests/CollectionTest.php
@@ -1,4 +1,5 @@
 <?php
+declare(strict_types=1);
 
 use Jenssegers\Mongodb\Connection;
 use Jenssegers\Mongodb\Collection;
diff --git a/tests/ConnectionTest.php b/tests/ConnectionTest.php
index 2ca7c319e..777169a06 100644
--- a/tests/ConnectionTest.php
+++ b/tests/ConnectionTest.php
@@ -1,11 +1,14 @@
 <?php
+declare(strict_types=1);
+
+use Illuminate\Support\Facades\DB;
 
 class ConnectionTest extends TestCase
 {
     public function testConnection()
     {
         $connection = DB::connection('mongodb');
-        $this->assertInstanceOf('Jenssegers\Mongodb\Connection', $connection);
+        $this->assertInstanceOf(\Jenssegers\Mongodb\Connection::class, $connection);
     }
 
     public function testReconnect()
@@ -23,22 +26,22 @@ public function testReconnect()
     public function testDb()
     {
         $connection = DB::connection('mongodb');
-        $this->assertInstanceOf('MongoDB\Database', $connection->getMongoDB());
+        $this->assertInstanceOf(\MongoDB\Database::class, $connection->getMongoDB());
 
         $connection = DB::connection('mongodb');
-        $this->assertInstanceOf('MongoDB\Client', $connection->getMongoClient());
+        $this->assertInstanceOf(\MongoDB\Client::class, $connection->getMongoClient());
     }
 
     public function testCollection()
     {
         $collection = DB::connection('mongodb')->getCollection('unittest');
-        $this->assertInstanceOf('Jenssegers\Mongodb\Collection', $collection);
+        $this->assertInstanceOf(Jenssegers\Mongodb\Collection::class, $collection);
 
         $collection = DB::connection('mongodb')->collection('unittests');
-        $this->assertInstanceOf('Jenssegers\Mongodb\Query\Builder', $collection);
+        $this->assertInstanceOf(Jenssegers\Mongodb\Query\Builder::class, $collection);
 
         $collection = DB::connection('mongodb')->table('unittests');
-        $this->assertInstanceOf('Jenssegers\Mongodb\Query\Builder', $collection);
+        $this->assertInstanceOf(Jenssegers\Mongodb\Query\Builder::class, $collection);
     }
 
     // public function testDynamic()
@@ -87,7 +90,7 @@ public function testQueryLog()
     public function testSchemaBuilder()
     {
         $schema = DB::connection('mongodb')->getSchemaBuilder();
-        $this->assertInstanceOf('Jenssegers\Mongodb\Schema\Builder', $schema);
+        $this->assertInstanceOf(\Jenssegers\Mongodb\Schema\Builder::class, $schema);
     }
 
     public function testDriverName()
diff --git a/tests/DsnTest.php b/tests/DsnTest.php
index 08fa0a8aa..2eed354f4 100644
--- a/tests/DsnTest.php
+++ b/tests/DsnTest.php
@@ -1,4 +1,5 @@
 <?php
+declare(strict_types=1);
 
 class DsnTest extends TestCase
 {
diff --git a/tests/EmbeddedRelationsTest.php b/tests/EmbeddedRelationsTest.php
index 440761e78..93af2180f 100644
--- a/tests/EmbeddedRelationsTest.php
+++ b/tests/EmbeddedRelationsTest.php
@@ -1,4 +1,5 @@
 <?php
+declare(strict_types=1);
 
 class EmbeddedRelationsTest extends TestCase
 {
@@ -20,7 +21,7 @@ public function testEmbedsManySave()
         $user = User::create(['name' => 'John Doe']);
         $address = new Address(['city' => 'London']);
 
-        $address->setEventDispatcher($events = Mockery::mock('Illuminate\Events\Dispatcher'));
+        $address->setEventDispatcher($events = Mockery::mock(\Illuminate\Events\Dispatcher::class));
         $events->shouldReceive('dispatch')->with('eloquent.retrieved: ' . get_class($address), Mockery::any());
         $events->shouldReceive('until')->once()->with('eloquent.saving: ' . get_class($address), $address)->andReturn(true);
         $events->shouldReceive('until')->once()->with('eloquent.creating: ' . get_class($address), $address)->andReturn(true);
@@ -31,7 +32,7 @@ public function testEmbedsManySave()
         $address->unsetEventDispatcher();
 
         $this->assertNotNull($user->addresses);
-        $this->assertInstanceOf('Illuminate\Database\Eloquent\Collection', $user->addresses);
+        $this->assertInstanceOf(\Illuminate\Database\Eloquent\Collection::class, $user->addresses);
         $this->assertEquals(['London'], $user->addresses->pluck('city')->all());
         $this->assertInstanceOf('DateTime', $address->created_at);
         $this->assertInstanceOf('DateTime', $address->updated_at);
@@ -39,14 +40,14 @@ public function testEmbedsManySave()
         $this->assertInternalType('string', $address->_id);
 
         $raw = $address->getAttributes();
-        $this->assertInstanceOf('MongoDB\BSON\ObjectID', $raw['_id']);
+        $this->assertInstanceOf(\MongoDB\BSON\ObjectID::class, $raw['_id']);
 
         $address = $user->addresses()->save(new Address(['city' => 'Paris']));
 
         $user = User::find($user->_id);
         $this->assertEquals(['London', 'Paris'], $user->addresses->pluck('city')->all());
 
-        $address->setEventDispatcher($events = Mockery::mock('Illuminate\Events\Dispatcher'));
+        $address->setEventDispatcher($events = Mockery::mock(\Illuminate\Events\Dispatcher::class));
         $events->shouldReceive('dispatch')->with('eloquent.retrieved: ' . get_class($address), Mockery::any());
         $events->shouldReceive('until')->once()->with('eloquent.saving: ' . get_class($address), $address)->andReturn(true);
         $events->shouldReceive('until')->once()->with('eloquent.updating: ' . get_class($address), $address)->andReturn(true);
@@ -91,7 +92,7 @@ public function testEmbedsManySave()
     //     $user = User::create(['name' => 'John Doe']);
     //     $address = new Address(['city' => 'London']);
 
-    //     $address->setEventDispatcher($events = Mockery::mock('Illuminate\Events\Dispatcher'));
+    //     $address->setEventDispatcher($events = Mockery::mock(\Illuminate\Events\Dispatcher::class));
     //     $events->shouldReceive('until')->once()->with('eloquent.saving: ' . get_class($address), $address)->andReturn(true);
     //     $events->shouldReceive('until')->once()->with('eloquent.creating: ' . get_class($address), $address)->andReturn(true);
     //     $events->shouldReceive('dispatch')->once()->with('eloquent.created: ' . get_class($address), $address);
@@ -99,7 +100,7 @@ public function testEmbedsManySave()
 
     //     $address->save();
 
-    //     $address->setEventDispatcher($events = Mockery::mock('Illuminate\Events\Dispatcher'));
+    //     $address->setEventDispatcher($events = Mockery::mock(\Illuminate\Events\Dispatcher::class));
     //     $events->shouldReceive('until')->once()->with('eloquent.saving: ' . get_class($address), $address)->andReturn(true);
     //     $events->shouldReceive('until')->once()->with('eloquent.updating: ' . get_class($address), $address)->andReturn(true);
     //     $events->shouldReceive('dispatch')->once()->with('eloquent.updated: ' . get_class($address), $address);
@@ -180,7 +181,7 @@ public function testEmbedsManyCreate()
         $this->assertEquals(['Bruxelles'], $user->addresses->pluck('city')->all());
 
         $raw = $address->getAttributes();
-        $this->assertInstanceOf('MongoDB\BSON\ObjectID', $raw['_id']);
+        $this->assertInstanceOf(\MongoDB\BSON\ObjectID::class, $raw['_id']);
 
         $freshUser = User::find($user->id);
         $this->assertEquals(['Bruxelles'], $freshUser->addresses->pluck('city')->all());
@@ -190,7 +191,7 @@ public function testEmbedsManyCreate()
         $this->assertInternalType('string', $address->_id);
 
         $raw = $address->getAttributes();
-        $this->assertInstanceOf('MongoDB\BSON\ObjectID', $raw['_id']);
+        $this->assertInstanceOf(\MongoDB\BSON\ObjectID::class, $raw['_id']);
     }
 
     public function testEmbedsManyCreateMany()
@@ -212,7 +213,7 @@ public function testEmbedsManyDestroy()
 
         $address = $user->addresses->first();
 
-        $address->setEventDispatcher($events = Mockery::mock('Illuminate\Events\Dispatcher'));
+        $address->setEventDispatcher($events = Mockery::mock(\Illuminate\Events\Dispatcher::class));
         $events->shouldReceive('dispatch')->with('eloquent.retrieved: ' . get_class($address), Mockery::any());
         $events->shouldReceive('until')->once()->with('eloquent.deleting: ' . get_class($address), Mockery::type('Address'))->andReturn(true);
         $events->shouldReceive('dispatch')->once()->with('eloquent.deleted: ' . get_class($address), Mockery::type('Address'));
@@ -251,7 +252,7 @@ public function testEmbedsManyDelete()
 
         $address = $user->addresses->first();
 
-        $address->setEventDispatcher($events = Mockery::mock('Illuminate\Events\Dispatcher'));
+        $address->setEventDispatcher($events = Mockery::mock(\Illuminate\Events\Dispatcher::class));
         $events->shouldReceive('dispatch')->with('eloquent.retrieved: ' . get_class($address), Mockery::any());
         $events->shouldReceive('until')->once()->with('eloquent.deleting: ' . get_class($address), Mockery::type('Address'))->andReturn(true);
         $events->shouldReceive('dispatch')->once()->with('eloquent.deleted: ' . get_class($address), Mockery::type('Address'));
@@ -300,7 +301,7 @@ public function testEmbedsManyCreatingEventReturnsFalse()
         $user = User::create(['name' => 'John Doe']);
         $address = new Address(['city' => 'London']);
 
-        $address->setEventDispatcher($events = Mockery::mock('Illuminate\Events\Dispatcher'));
+        $address->setEventDispatcher($events = Mockery::mock(\Illuminate\Events\Dispatcher::class));
         $events->shouldReceive('dispatch')->with('eloquent.retrieved: ' . get_class($address), Mockery::any());
         $events->shouldReceive('until')->once()->with('eloquent.saving: ' . get_class($address), $address)->andReturn(true);
         $events->shouldReceive('until')->once()->with('eloquent.creating: ' . get_class($address), $address)->andReturn(false);
@@ -315,7 +316,7 @@ public function testEmbedsManySavingEventReturnsFalse()
         $address = new Address(['city' => 'Paris']);
         $address->exists = true;
 
-        $address->setEventDispatcher($events = Mockery::mock('Illuminate\Events\Dispatcher'));
+        $address->setEventDispatcher($events = Mockery::mock(\Illuminate\Events\Dispatcher::class));
         $events->shouldReceive('dispatch')->with('eloquent.retrieved: ' . get_class($address), Mockery::any());
         $events->shouldReceive('until')->once()->with('eloquent.saving: ' . get_class($address), $address)->andReturn(false);
 
@@ -329,7 +330,7 @@ public function testEmbedsManyUpdatingEventReturnsFalse()
         $address = new Address(['city' => 'New York']);
         $user->addresses()->save($address);
 
-        $address->setEventDispatcher($events = Mockery::mock('Illuminate\Events\Dispatcher'));
+        $address->setEventDispatcher($events = Mockery::mock(\Illuminate\Events\Dispatcher::class));
         $events->shouldReceive('dispatch')->with('eloquent.retrieved: ' . get_class($address), Mockery::any());
         $events->shouldReceive('until')->once()->with('eloquent.saving: ' . get_class($address), $address)->andReturn(true);
         $events->shouldReceive('until')->once()->with('eloquent.updating: ' . get_class($address), $address)->andReturn(false);
@@ -347,7 +348,7 @@ public function testEmbedsManyDeletingEventReturnsFalse()
 
         $address = $user->addresses->first();
 
-        $address->setEventDispatcher($events = Mockery::mock('Illuminate\Events\Dispatcher'));
+        $address->setEventDispatcher($events = Mockery::mock(\Illuminate\Events\Dispatcher::class));
         $events->shouldReceive('dispatch')->with('eloquent.retrieved: ' . get_class($address), Mockery::any());
         $events->shouldReceive('until')->once()->with('eloquent.deleting: ' . get_class($address), Mockery::mustBe($address))->andReturn(false);
 
@@ -451,7 +452,7 @@ public function testEmbedsOne()
         $user = User::create(['name' => 'John Doe']);
         $father = new User(['name' => 'Mark Doe']);
 
-        $father->setEventDispatcher($events = Mockery::mock('Illuminate\Events\Dispatcher'));
+        $father->setEventDispatcher($events = Mockery::mock(\Illuminate\Events\Dispatcher::class));
         $events->shouldReceive('dispatch')->with('eloquent.retrieved: ' . get_class($father), Mockery::any());
         $events->shouldReceive('until')->once()->with('eloquent.saving: ' . get_class($father), $father)->andReturn(true);
         $events->shouldReceive('until')->once()->with('eloquent.creating: ' . get_class($father), $father)->andReturn(true);
@@ -471,7 +472,7 @@ public function testEmbedsOne()
         $raw = $father->getAttributes();
         $this->assertInstanceOf('MongoDB\BSON\ObjectID', $raw['_id']);
 
-        $father->setEventDispatcher($events = Mockery::mock('Illuminate\Events\Dispatcher'));
+        $father->setEventDispatcher($events = Mockery::mock(\Illuminate\Events\Dispatcher::class));
         $events->shouldReceive('dispatch')->with('eloquent.retrieved: ' . get_class($father), Mockery::any());
         $events->shouldReceive('until')->once()->with('eloquent.saving: ' . get_class($father), $father)->andReturn(true);
         $events->shouldReceive('until')->once()->with('eloquent.updating: ' . get_class($father), $father)->andReturn(true);
@@ -487,7 +488,7 @@ public function testEmbedsOne()
 
         $father = new User(['name' => 'Jim Doe']);
 
-        $father->setEventDispatcher($events = Mockery::mock('Illuminate\Events\Dispatcher'));
+        $father->setEventDispatcher($events = Mockery::mock(\Illuminate\Events\Dispatcher::class));
         $events->shouldReceive('dispatch')->with('eloquent.retrieved: ' . get_class($father), Mockery::any());
         $events->shouldReceive('until')->once()->with('eloquent.saving: ' . get_class($father), $father)->andReturn(true);
         $events->shouldReceive('until')->once()->with('eloquent.creating: ' . get_class($father), $father)->andReturn(true);
@@ -506,7 +507,7 @@ public function testEmbedsOneAssociate()
         $user = User::create(['name' => 'John Doe']);
         $father = new User(['name' => 'Mark Doe']);
 
-        $father->setEventDispatcher($events = Mockery::mock('Illuminate\Events\Dispatcher'));
+        $father->setEventDispatcher($events = Mockery::mock(\Illuminate\Events\Dispatcher::class));
         $events->shouldReceive('dispatch')->with('eloquent.retrieved: ' . get_class($father), Mockery::any());
         $events->shouldReceive('until')->times(0)->with('eloquent.saving: ' . get_class($father), $father);
 
@@ -534,6 +535,7 @@ public function testEmbedsOneDelete()
 
     public function testEmbedsManyToArray()
     {
+        /** @var User $user */
         $user = User::create(['name' => 'John Doe']);
         $user->addresses()->save(new Address(['city' => 'New York']));
         $user->addresses()->save(new Address(['city' => 'Paris']));
@@ -546,7 +548,9 @@ public function testEmbedsManyToArray()
 
     public function testEmbeddedSave()
     {
+        /** @var User $user */
         $user = User::create(['name' => 'John Doe']);
+        /** @var \Address $address */
         $address = $user->addresses()->create(['city' => 'New York']);
         $father = $user->father()->create(['name' => 'Mark Doe']);
 
diff --git a/tests/GeospatialTest.php b/tests/GeospatialTest.php
index b13ed46af..f1237e582 100644
--- a/tests/GeospatialTest.php
+++ b/tests/GeospatialTest.php
@@ -1,4 +1,5 @@
 <?php
+declare(strict_types=1);
 
 class GeospatialTest extends TestCase
 {
diff --git a/tests/HybridRelationsTest.php b/tests/HybridRelationsTest.php
index ade509067..832eb6f86 100644
--- a/tests/HybridRelationsTest.php
+++ b/tests/HybridRelationsTest.php
@@ -1,4 +1,5 @@
 <?php
+declare(strict_types=1);
 
 class HybridRelationsTest extends TestCase
 {
diff --git a/tests/ModelTest.php b/tests/ModelTest.php
index f6e4f4eb6..e68b00cb0 100644
--- a/tests/ModelTest.php
+++ b/tests/ModelTest.php
@@ -1,7 +1,9 @@
 <?php
+declare(strict_types=1);
 
 use Carbon\Carbon;
 use Illuminate\Database\Eloquent\Collection;
+use Illuminate\Database\Eloquent\ModelNotFoundException;
 use Jenssegers\Mongodb\Eloquent\Model;
 use MongoDB\BSON\ObjectID;
 use MongoDB\BSON\UTCDateTime;
@@ -16,17 +18,17 @@ public function tearDown(): void
         Item::truncate();
     }
 
-    public function testNewModel()
+    public function testNewModel(): void
     {
         $user = new User;
         $this->assertInstanceOf(Model::class, $user);
-        $this->assertInstanceOf('Jenssegers\Mongodb\Connection', $user->getConnection());
+        $this->assertInstanceOf(\Jenssegers\Mongodb\Connection::class, $user->getConnection());
         $this->assertFalse($user->exists);
         $this->assertEquals('users', $user->getTable());
         $this->assertEquals('_id', $user->getKeyName());
     }
 
-    public function testInsert()
+    public function testInsert(): void
     {
         $user = new User;
         $user->name = 'John Doe';
@@ -51,7 +53,7 @@ public function testInsert()
         $this->assertEquals(35, $user->age);
     }
 
-    public function testUpdate()
+    public function testUpdate(): void
     {
         $user = new User;
         $user->name = 'John Doe';
@@ -62,8 +64,8 @@ public function testUpdate()
         $raw = $user->getAttributes();
         $this->assertInstanceOf(ObjectID::class, $raw['_id']);
 
+        /** @var User $check */
         $check = User::find($user->_id);
-
         $check->age = 36;
         $check->save();
 
@@ -84,7 +86,7 @@ public function testUpdate()
         $this->assertEquals(20, $check->age);
     }
 
-    public function testManualStringId()
+    public function testManualStringId(): void
     {
         $user = new User;
         $user->_id = '4af9f23d8ead0e1d32000000';
@@ -113,7 +115,7 @@ public function testManualStringId()
         $this->assertInternalType('string', $raw['_id']);
     }
 
-    public function testManualIntId()
+    public function testManualIntId(): void
     {
         $user = new User;
         $user->_id = 1;
@@ -129,7 +131,7 @@ public function testManualIntId()
         $this->assertInternalType('integer', $raw['_id']);
     }
 
-    public function testDelete()
+    public function testDelete(): void
     {
         $user = new User;
         $user->name = 'John Doe';
@@ -145,7 +147,7 @@ public function testDelete()
         $this->assertEquals(0, User::count());
     }
 
-    public function testAll()
+    public function testAll(): void
     {
         $user = new User;
         $user->name = 'John Doe';
@@ -166,7 +168,7 @@ public function testAll()
         $this->assertContains('Jane Doe', $all->pluck('name'));
     }
 
-    public function testFind()
+    public function testFind(): void
     {
         $user = new User;
         $user->name = 'John Doe';
@@ -174,6 +176,7 @@ public function testFind()
         $user->age = 35;
         $user->save();
 
+        /** @var User $check */
         $check = User::find($user->_id);
 
         $this->assertInstanceOf(Model::class, $check);
@@ -184,7 +187,7 @@ public function testFind()
         $this->assertEquals(35, $check->age);
     }
 
-    public function testGet()
+    public function testGet(): void
     {
         User::insert([
             ['name' => 'John Doe'],
@@ -197,19 +200,20 @@ public function testGet()
         $this->assertInstanceOf(Model::class, $users[0]);
     }
 
-    public function testFirst()
+    public function testFirst(): void
     {
         User::insert([
             ['name' => 'John Doe'],
             ['name' => 'Jane Doe'],
         ]);
 
+        /** @var User $user */
         $user = User::first();
         $this->assertInstanceOf(Model::class, $user);
         $this->assertEquals('John Doe', $user->name);
     }
 
-    public function testNoDocument()
+    public function testNoDocument(): void
     {
         $items = Item::where('name', 'nothing')->get();
         $this->assertInstanceOf(Collection::class, $items);
@@ -222,25 +226,27 @@ public function testNoDocument()
         $this->assertNull($item);
     }
 
-    public function testFindOrfail()
+    public function testFindOrFail(): void
     {
-        $this->expectException(Illuminate\Database\Eloquent\ModelNotFoundException::class);
-        User::findOrfail('51c33d8981fec6813e00000a');
+        $this->expectException(ModelNotFoundException::class);
+        User::findOrFail('51c33d8981fec6813e00000a');
     }
 
-    public function testCreate()
+    public function testCreate(): void
     {
+        /** @var User $user */
         $user = User::create(['name' => 'Jane Poe']);
 
         $this->assertInstanceOf(Model::class, $user);
         $this->assertTrue($user->exists);
         $this->assertEquals('Jane Poe', $user->name);
 
+        /** @var User $check */
         $check = User::where('name', 'Jane Poe')->first();
         $this->assertEquals($user->_id, $check->_id);
     }
 
-    public function testDestroy()
+    public function testDestroy(): void
     {
         $user = new User;
         $user->name = 'John Doe';
@@ -253,7 +259,7 @@ public function testDestroy()
         $this->assertEquals(0, User::count());
     }
 
-    public function testTouch()
+    public function testTouch(): void
     {
         $user = new User;
         $user->name = 'John Doe';
@@ -264,18 +270,21 @@ public function testTouch()
         $old = $user->updated_at;
         sleep(1);
         $user->touch();
+
+        /** @var User $check */
         $check = User::find($user->_id);
 
         $this->assertNotEquals($old, $check->updated_at);
     }
 
-    public function testSoftDelete()
+    public function testSoftDelete(): void
     {
         Soft::create(['name' => 'John Doe']);
         Soft::create(['name' => 'Jane Doe']);
 
         $this->assertEquals(2, Soft::count());
 
+        /** @var Soft $user */
         $user = Soft::where('name', 'John Doe')->first();
         $this->assertTrue($user->exists);
         $this->assertFalse($user->trashed());
@@ -300,7 +309,7 @@ public function testSoftDelete()
         $this->assertEquals(2, Soft::count());
     }
 
-    public function testPrimaryKey()
+    public function testPrimaryKey(): void
     {
         $user = new User;
         $this->assertEquals('_id', $user->getKeyName());
@@ -314,13 +323,14 @@ public function testPrimaryKey()
 
         $this->assertEquals('A Game of Thrones', $book->getKey());
 
+        /** @var Book $check */
         $check = Book::find('A Game of Thrones');
         $this->assertEquals('title', $check->getKeyName());
         $this->assertEquals('A Game of Thrones', $check->getKey());
         $this->assertEquals('A Game of Thrones', $check->title);
     }
 
-    public function testScope()
+    public function testScope(): void
     {
         Item::insert([
             ['name' => 'knife', 'type' => 'sharp'],
@@ -331,7 +341,7 @@ public function testScope()
         $this->assertEquals(1, $sharp->count());
     }
 
-    public function testToArray()
+    public function testToArray(): void
     {
         $item = Item::create(['name' => 'fork', 'type' => 'sharp']);
 
@@ -344,7 +354,7 @@ public function testToArray()
         $this->assertInternalType('string', $array['_id']);
     }
 
-    public function testUnset()
+    public function testUnset(): void
     {
         $user1 = User::create(['name' => 'John Doe', 'note1' => 'ABC', 'note2' => 'DEF']);
         $user2 = User::create(['name' => 'Jane Doe', 'note1' => 'ABC', 'note2' => 'DEF']);
@@ -371,7 +381,7 @@ public function testUnset()
         $this->assertObjectNotHasAttribute('note2', $user2);
     }
 
-    public function testDates()
+    public function testDates(): void
     {
         $birthday = new DateTime('1980/1/1');
         $user = User::create(['name' => 'John Doe', 'birthday' => $birthday]);
@@ -398,10 +408,12 @@ public function testDates()
         $this->assertLessThan(2, abs(time() - $item->created_at->getTimestamp()));
 
         // test default date format for json output
+        /** @var Item $item */
         $item = Item::create(['name' => 'sword']);
         $json = $item->toArray();
         $this->assertEquals($item->created_at->format('Y-m-d H:i:s'), $json['created_at']);
 
+        /** @var User $user */
         $user = User::create(['name' => 'Jane Doe', 'birthday' => time()]);
         $this->assertInstanceOf(Carbon::class, $user->birthday);
 
@@ -422,8 +434,9 @@ public function testDates()
         $this->assertEquals((string) $user->getAttribute('entry.date')->format('Y-m-d H:i:s'), $data['entry']['date']);
     }
 
-    public function testIdAttribute()
+    public function testIdAttribute(): void
     {
+        /** @var User $user */
         $user = User::create(['name' => 'John Doe']);
         $this->assertEquals($user->id, $user->_id);
 
@@ -431,8 +444,9 @@ public function testIdAttribute()
         $this->assertNotEquals($user->id, $user->_id);
     }
 
-    public function testPushPull()
+    public function testPushPull(): void
     {
+        /** @var User $user */
         $user = User::create(['name' => 'John Doe']);
 
         $user->push('tags', 'tag1');
@@ -457,36 +471,36 @@ public function testPushPull()
         $this->assertEquals([], $user->tags);
     }
 
-    public function testRaw()
+    public function testRaw(): void
     {
         User::create(['name' => 'John Doe', 'age' => 35]);
         User::create(['name' => 'Jane Doe', 'age' => 35]);
         User::create(['name' => 'Harry Hoe', 'age' => 15]);
 
-        $users = User::raw(function ($collection) {
+        $users = User::raw(function (\Jenssegers\Mongodb\Collection $collection) {
             return $collection->find(['age' => 35]);
         });
         $this->assertInstanceOf(Collection::class, $users);
         $this->assertInstanceOf(Model::class, $users[0]);
 
-        $user = User::raw(function ($collection) {
+        $user = User::raw(function (\Jenssegers\Mongodb\Collection $collection) {
             return $collection->findOne(['age' => 35]);
         });
 
         $this->assertInstanceOf(Model::class, $user);
 
-        $count = User::raw(function ($collection) {
+        $count = User::raw(function (\Jenssegers\Mongodb\Collection $collection) {
             return $collection->count();
         });
         $this->assertEquals(3, $count);
 
-        $result = User::raw(function ($collection) {
+        $result = User::raw(function (\Jenssegers\Mongodb\Collection $collection) {
             return $collection->insertOne(['name' => 'Yvonne Yoe', 'age' => 35]);
         });
         $this->assertNotNull($result);
     }
 
-    public function testDotNotation()
+    public function testDotNotation(): void
     {
         $user = User::create([
             'name' => 'John Doe',
@@ -508,8 +522,9 @@ public function testDotNotation()
         $this->assertEquals('Strasbourg', $user['address.city']);
     }
 
-    public function testMultipleLevelDotNotation()
+    public function testMultipleLevelDotNotation(): void
     {
+        /** @var Book $book */
         $book = Book::create([
             'title' => 'A Game of Thrones',
             'chapters' => [
@@ -524,7 +539,7 @@ public function testMultipleLevelDotNotation()
         $this->assertEquals('The first chapter', $book['chapters.one.title']);
     }
 
-    public function testGetDirtyDates()
+    public function testGetDirtyDates(): void
     {
         $user = new User();
         $user->setRawAttributes(['name' => 'John Doe', 'birthday' => new DateTime('19 august 1989')], true);
@@ -534,14 +549,14 @@ public function testGetDirtyDates()
         $this->assertEmpty($user->getDirty());
     }
 
-    public function testChunkById()
+    public function testChunkById(): void
     {
         User::create(['name' => 'fork',  'tags' => ['sharp', 'pointy']]);
         User::create(['name' => 'spork', 'tags' => ['sharp', 'pointy', 'round', 'bowl']]);
         User::create(['name' => 'spoon', 'tags' => ['round', 'bowl']]);
 
         $count = 0;
-        User::chunkById(2, function ($items) use (&$count) {
+        User::chunkById(2, function (\Illuminate\Database\Eloquent\Collection $items) use (&$count) {
             $count += count($items);
         });
 
diff --git a/tests/QueryBuilderTest.php b/tests/QueryBuilderTest.php
index 097ded65b..4b1321684 100644
--- a/tests/QueryBuilderTest.php
+++ b/tests/QueryBuilderTest.php
@@ -1,5 +1,7 @@
 <?php
+declare(strict_types=1);
 
+use Illuminate\Support\Facades\DB;
 use MongoDB\BSON\UTCDateTime;
 use MongoDB\BSON\Regex;
 
diff --git a/tests/QueryTest.php b/tests/QueryTest.php
index 0175fd2ad..646340ad2 100644
--- a/tests/QueryTest.php
+++ b/tests/QueryTest.php
@@ -1,4 +1,5 @@
 <?php
+declare(strict_types=1);
 
 class QueryTest extends TestCase
 {
@@ -25,7 +26,7 @@ public function tearDown(): void
         parent::tearDown();
     }
 
-    public function testWhere()
+    public function testWhere(): void
     {
         $users = User::where('age', 35)->get();
         $this->assertCount(3, $users);
@@ -46,7 +47,7 @@ public function testWhere()
         $this->assertCount(6, $users);
     }
 
-    public function testAndWhere()
+    public function testAndWhere(): void
     {
         $users = User::where('age', 35)->where('title', 'admin')->get();
         $this->assertCount(2, $users);
@@ -55,7 +56,7 @@ public function testAndWhere()
         $this->assertCount(2, $users);
     }
 
-    public function testLike()
+    public function testLike(): void
     {
         $users = User::where('name', 'like', '%doe')->get();
         $this->assertCount(2, $users);
@@ -70,7 +71,7 @@ public function testLike()
         $this->assertCount(1, $users);
     }
 
-    public function testSelect()
+    public function testSelect(): void
     {
         $user = User::where('name', 'John Doe')->select('name')->first();
 
@@ -96,7 +97,7 @@ public function testSelect()
         $this->assertNull($user->age);
     }
 
-    public function testOrWhere()
+    public function testOrWhere(): void
     {
         $users = User::where('age', 13)->orWhere('title', 'admin')->get();
         $this->assertCount(4, $users);
@@ -105,7 +106,7 @@ public function testOrWhere()
         $this->assertCount(2, $users);
     }
 
-    public function testBetween()
+    public function testBetween(): void
     {
         $users = User::whereBetween('age', [0, 25])->get();
         $this->assertCount(2, $users);
@@ -118,7 +119,7 @@ public function testBetween()
         $this->assertCount(6, $users);
     }
 
-    public function testIn()
+    public function testIn(): void
     {
         $users = User::whereIn('age', [13, 23])->get();
         $this->assertCount(2, $users);
@@ -134,19 +135,19 @@ public function testIn()
         $this->assertCount(3, $users);
     }
 
-    public function testWhereNull()
+    public function testWhereNull(): void
     {
         $users = User::whereNull('age')->get();
         $this->assertCount(1, $users);
     }
 
-    public function testWhereNotNull()
+    public function testWhereNotNull(): void
     {
         $users = User::whereNotNull('age')->get();
         $this->assertCount(8, $users);
     }
 
-    public function testOrder()
+    public function testOrder(): void
     {
         $user = User::whereNotNull('age')->orderBy('age', 'asc')->first();
         $this->assertEquals(13, $user->age);
@@ -167,7 +168,7 @@ public function testOrder()
         $this->assertEquals(35, $user->age);
     }
 
-    public function testGroupBy()
+    public function testGroupBy(): void
     {
         $users = User::groupBy('title')->get();
         $this->assertCount(3, $users);
@@ -197,7 +198,7 @@ public function testGroupBy()
         $this->assertNotNull($users[0]->name);
     }
 
-    public function testCount()
+    public function testCount(): void
     {
         $count = User::where('age', '<>', 35)->count();
         $this->assertEquals(6, $count);
@@ -207,13 +208,13 @@ public function testCount()
         $this->assertEquals(6, $count);
     }
 
-    public function testExists()
+    public function testExists(): void
     {
         $this->assertFalse(User::where('age', '>', 37)->exists());
         $this->assertTrue(User::where('age', '<', 37)->exists());
     }
 
-    public function testSubquery()
+    public function testSubQuery(): void
     {
         $users = User::where('title', 'admin')->orWhere(function ($query) {
             $query->where('name', 'Tommy Toe')
@@ -262,7 +263,7 @@ public function testSubquery()
         $this->assertEquals(5, $users->count());
     }
 
-    public function testWhereRaw()
+    public function testWhereRaw(): void
     {
         $where = ['age' => ['$gt' => 30, '$lt' => 40]];
         $users = User::whereRaw($where)->get();
@@ -276,7 +277,7 @@ public function testWhereRaw()
         $this->assertCount(6, $users);
     }
 
-    public function testMultipleOr()
+    public function testMultipleOr(): void
     {
         $users = User::where(function ($query) {
             $query->where('age', 35)->orWhere('age', 33);
@@ -297,7 +298,7 @@ public function testMultipleOr()
         $this->assertCount(2, $users);
     }
 
-    public function testPaginate()
+    public function testPaginate(): void
     {
         $results = User::paginate(2);
         $this->assertEquals(2, $results->count());
@@ -311,7 +312,7 @@ public function testPaginate()
         $this->assertEquals(1, $results->currentPage());
     }
 
-    public function testUpdate()
+    public function testUpdate(): void
     {
         $this->assertEquals(1, User::where(['name' => 'John Doe'])->update(['name' => 'Jim Morrison']));
         $this->assertEquals(1, User::where(['name' => 'Jim Morrison'])->count());
diff --git a/tests/QueueTest.php b/tests/QueueTest.php
index 7502ce6f7..6ff26d35c 100644
--- a/tests/QueueTest.php
+++ b/tests/QueueTest.php
@@ -1,4 +1,5 @@
 <?php
+declare(strict_types=1);
 
 class QueueTest extends TestCase
 {
@@ -11,7 +12,7 @@ public function setUp(): void
         Queue::getDatabase()->table(Config::get('queue.failed.table'))->truncate();
     }
 
-    public function testQueueJobLifeCycle()
+    public function testQueueJobLifeCycle(): void
     {
         $id = Queue::push('test', ['action' => 'QueueJobLifeCycle'], 'test');
         $this->assertNotNull($id);
@@ -34,7 +35,7 @@ public function testQueueJobLifeCycle()
         $this->assertEquals(0, Queue::getDatabase()->table(Config::get('queue.connections.database.table'))->count());
     }
 
-    public function testQueueJobExpired()
+    public function testQueueJobExpired(): void
     {
         $id = Queue::push('test', ['action' => 'QueueJobExpired'], 'test');
         $this->assertNotNull($id);
diff --git a/tests/RelationsTest.php b/tests/RelationsTest.php
index de3e0f222..decc4f14b 100644
--- a/tests/RelationsTest.php
+++ b/tests/RelationsTest.php
@@ -1,4 +1,5 @@
 <?php
+declare(strict_types=1);
 
 class RelationsTest extends TestCase
 {
@@ -17,7 +18,7 @@ public function tearDown(): void
         Photo::truncate();
     }
 
-    public function testHasMany()
+    public function testHasMany(): void
     {
         $author = User::create(['name' => 'George R. R. Martin']);
         Book::create(['title' => 'A Game of Thrones', 'author_id' => $author->_id]);
@@ -36,7 +37,7 @@ public function testHasMany()
         $this->assertCount(3, $items);
     }
 
-    public function testBelongsTo()
+    public function testBelongsTo(): void
     {
         $user = User::create(['name' => 'George R. R. Martin']);
         Book::create(['title' => 'A Game of Thrones', 'author_id' => $user->_id]);
@@ -55,7 +56,7 @@ public function testBelongsTo()
         $this->assertNull($book->author);
     }
 
-    public function testHasOne()
+    public function testHasOne(): void
     {
         $user = User::create(['name' => 'John Doe']);
         Role::create(['type' => 'admin', 'user_id' => $user->_id]);
@@ -78,7 +79,7 @@ public function testHasOne()
         $this->assertEquals($user->_id, $role->user_id);
     }
 
-    public function testWithBelongsTo()
+    public function testWithBelongsTo(): void
     {
         $user = User::create(['name' => 'John Doe']);
         Item::create(['type' => 'knife', 'user_id' => $user->_id]);
@@ -95,7 +96,7 @@ public function testWithBelongsTo()
         $this->assertNull($items[3]->getRelation('user'));
     }
 
-    public function testWithHashMany()
+    public function testWithHashMany(): void
     {
         $user = User::create(['name' => 'John Doe']);
         Item::create(['type' => 'knife', 'user_id' => $user->_id]);
@@ -110,7 +111,7 @@ public function testWithHashMany()
         $this->assertInstanceOf('Item', $items[0]);
     }
 
-    public function testWithHasOne()
+    public function testWithHasOne(): void
     {
         $user = User::create(['name' => 'John Doe']);
         Role::create(['type' => 'admin', 'user_id' => $user->_id]);
@@ -123,7 +124,7 @@ public function testWithHasOne()
         $this->assertEquals('admin', $role->type);
     }
 
-    public function testEasyRelation()
+    public function testEasyRelation(): void
     {
         // Has Many
         $user = User::create(['name' => 'John Doe']);
@@ -148,7 +149,7 @@ public function testEasyRelation()
         $this->assertEquals($user->_id, $role->user_id);
     }
 
-    public function testBelongsToMany()
+    public function testBelongsToMany(): void
     {
         $user = User::create(['name' => 'John Doe']);
 
@@ -222,7 +223,7 @@ public function testBelongsToMany()
         $this->assertCount(1, $client->users);
     }
 
-    public function testBelongsToManyAttachesExistingModels()
+    public function testBelongsToManyAttachesExistingModels(): void
     {
         $user = User::create(['name' => 'John Doe', 'client_ids' => ['1234523']]);
 
@@ -261,7 +262,7 @@ public function testBelongsToManyAttachesExistingModels()
         $this->assertStringStartsWith('synced', $user->clients[1]->name);
     }
 
-    public function testBelongsToManySync()
+    public function testBelongsToManySync(): void
     {
         // create test instances
         $user = User::create(['name' => 'John Doe']);
@@ -280,7 +281,7 @@ public function testBelongsToManySync()
         $this->assertCount(1, $user->clients);
     }
 
-    public function testBelongsToManyAttachArray()
+    public function testBelongsToManyAttachArray(): void
     {
         $user = User::create(['name' => 'John Doe']);
         $client1 = Client::create(['name' => 'Test 1'])->_id;
@@ -291,7 +292,7 @@ public function testBelongsToManyAttachArray()
         $this->assertCount(2, $user->clients);
     }
 
-    public function testBelongsToManyAttachEloquentCollection()
+    public function testBelongsToManyAttachEloquentCollection(): void
     {
         $user = User::create(['name' => 'John Doe']);
         $client1 = Client::create(['name' => 'Test 1']);
@@ -303,7 +304,7 @@ public function testBelongsToManyAttachEloquentCollection()
         $this->assertCount(2, $user->clients);
     }
 
-    public function testBelongsToManySyncAlreadyPresent()
+    public function testBelongsToManySyncAlreadyPresent(): void
     {
         $user = User::create(['name' => 'John Doe']);
         $client1 = Client::create(['name' => 'Test 1'])->_id;
@@ -320,7 +321,7 @@ public function testBelongsToManySyncAlreadyPresent()
         $this->assertCount(1, $user['client_ids']);
     }
 
-    public function testBelongsToManyCustom()
+    public function testBelongsToManyCustom(): void
     {
         $user = User::create(['name' => 'John Doe']);
         $group = $user->groups()->create(['name' => 'Admins']);
@@ -340,7 +341,7 @@ public function testBelongsToManyCustom()
         $this->assertEquals($user->_id, $group->users()->first()->_id);
     }
 
-    public function testMorph()
+    public function testMorph(): void
     {
         $user = User::create(['name' => 'John Doe']);
         $client = Client::create(['name' => 'Jane Doe']);
@@ -383,7 +384,7 @@ public function testMorph()
         $this->assertInstanceOf('Client', $photos[1]->imageable);
     }
 
-    public function testHasManyHas()
+    public function testHasManyHas(): void
     {
         $author1 = User::create(['name' => 'George R. R. Martin']);
         $author1->books()->create(['title' => 'A Game of Thrones', 'rating' => 5]);
@@ -433,7 +434,7 @@ public function testHasManyHas()
         $this->assertCount(1, $authors);
     }
 
-    public function testHasOneHas()
+    public function testHasOneHas(): void
     {
         $user1 = User::create(['name' => 'John Doe']);
         $user1->role()->create(['title' => 'admin']);
@@ -455,7 +456,7 @@ public function testHasOneHas()
         $this->assertCount(2, $users);
     }
 
-    public function testNestedKeys()
+    public function testNestedKeys(): void
     {
         $client = Client::create([
             'data' => [
@@ -481,7 +482,7 @@ public function testNestedKeys()
         $this->assertEquals('Paris', $client->addresses->first()->data['city']);
     }
 
-    public function testDoubleSaveOneToMany()
+    public function testDoubleSaveOneToMany(): void
     {
         $author = User::create(['name' => 'George R. R. Martin']);
         $book = Book::create(['title' => 'A Game of Thrones']);
@@ -504,7 +505,7 @@ public function testDoubleSaveOneToMany()
         $this->assertEquals($author->_id, $book->author_id);
     }
 
-    public function testDoubleSaveManyToMany()
+    public function testDoubleSaveManyToMany(): void
     {
         $user = User::create(['name' => 'John Doe']);
         $client = Client::create(['name' => 'Admins']);
diff --git a/tests/SchemaTest.php b/tests/SchemaTest.php
index b56cc639c..a8fac2f1f 100644
--- a/tests/SchemaTest.php
+++ b/tests/SchemaTest.php
@@ -1,4 +1,5 @@
 <?php
+declare(strict_types=1);
 
 class SchemaTest extends TestCase
 {
@@ -8,14 +9,14 @@ public function tearDown(): void
         Schema::drop('newcollection_two');
     }
 
-    public function testCreate()
+    public function testCreate(): void
     {
         Schema::create('newcollection');
         $this->assertTrue(Schema::hasCollection('newcollection'));
         $this->assertTrue(Schema::hasTable('newcollection'));
     }
 
-    public function testCreateWithCallback()
+    public function testCreateWithCallback(): void
     {
         $instance = $this;
 
@@ -26,21 +27,21 @@ public function testCreateWithCallback()
         $this->assertTrue(Schema::hasCollection('newcollection'));
     }
 
-    public function testCreateWithOptions()
+    public function testCreateWithOptions(): void
     {
         Schema::create('newcollection_two', null, ['capped' => true, 'size' => 1024]);
         $this->assertTrue(Schema::hasCollection('newcollection_two'));
         $this->assertTrue(Schema::hasTable('newcollection_two'));
     }
 
-    public function testDrop()
+    public function testDrop(): void
     {
         Schema::create('newcollection');
         Schema::drop('newcollection');
         $this->assertFalse(Schema::hasCollection('newcollection'));
     }
 
-    public function testBluePrint()
+    public function testBluePrint(): void
     {
         $instance = $this;
 
@@ -53,7 +54,7 @@ public function testBluePrint()
         });
     }
 
-    public function testIndex()
+    public function testIndex(): void
     {
         Schema::collection('newcollection', function ($collection) {
             $collection->index('mykey1');
@@ -77,7 +78,7 @@ public function testIndex()
         $this->assertEquals(1, $index['key']['mykey3']);
     }
 
-    public function testPrimary()
+    public function testPrimary(): void
     {
         Schema::collection('newcollection', function ($collection) {
             $collection->string('mykey', 100)->primary();
@@ -87,7 +88,7 @@ public function testPrimary()
         $this->assertEquals(1, $index['unique']);
     }
 
-    public function testUnique()
+    public function testUnique(): void
     {
         Schema::collection('newcollection', function ($collection) {
             $collection->unique('uniquekey');
@@ -97,7 +98,7 @@ public function testUnique()
         $this->assertEquals(1, $index['unique']);
     }
 
-    public function testDropIndex()
+    public function testDropIndex(): void
     {
         Schema::collection('newcollection', function ($collection) {
             $collection->unique('uniquekey');
@@ -144,7 +145,7 @@ public function testDropIndex()
         $this->assertFalse($index);
     }
 
-    public function testBackground()
+    public function testBackground(): void
     {
         Schema::collection('newcollection', function ($collection) {
             $collection->background('backgroundkey');
@@ -154,7 +155,7 @@ public function testBackground()
         $this->assertEquals(1, $index['background']);
     }
 
-    public function testSparse()
+    public function testSparse(): void
     {
         Schema::collection('newcollection', function ($collection) {
             $collection->sparse('sparsekey');
@@ -164,7 +165,7 @@ public function testSparse()
         $this->assertEquals(1, $index['sparse']);
     }
 
-    public function testExpire()
+    public function testExpire(): void
     {
         Schema::collection('newcollection', function ($collection) {
             $collection->expire('expirekey', 60);
@@ -174,7 +175,7 @@ public function testExpire()
         $this->assertEquals(60, $index['expireAfterSeconds']);
     }
 
-    public function testSoftDeletes()
+    public function testSoftDeletes(): void
     {
         Schema::collection('newcollection', function ($collection) {
             $collection->softDeletes();
@@ -188,7 +189,7 @@ public function testSoftDeletes()
         $this->assertEquals(1, $index['key']['email']);
     }
 
-    public function testFluent()
+    public function testFluent(): void
     {
         Schema::collection('newcollection', function ($collection) {
             $collection->string('email')->index();
@@ -203,7 +204,7 @@ public function testFluent()
         $this->assertEquals(1, $index['key']['token']);
     }
 
-    public function testGeospatial()
+    public function testGeospatial(): void
     {
         Schema::collection('newcollection', function ($collection) {
             $collection->geospatial('point');
@@ -221,7 +222,7 @@ public function testGeospatial()
         $this->assertEquals('2dsphere', $index['key']['continent']);
     }
 
-    public function testDummies()
+    public function testDummies(): void
     {
         Schema::collection('newcollection', function ($collection) {
             $collection->boolean('activated')->default(0);
@@ -229,7 +230,7 @@ public function testDummies()
         });
     }
 
-    public function testSparseUnique()
+    public function testSparseUnique(): void
     {
         Schema::collection('newcollection', function ($collection) {
             $collection->sparse_and_unique('sparseuniquekey');
@@ -240,7 +241,7 @@ public function testSparseUnique()
         $this->assertEquals(1, $index['unique']);
     }
 
-    protected function getIndex($collection, $name)
+    protected function getIndex(string $collection, string $name)
     {
         $collection = DB::getCollection($collection);
 
diff --git a/tests/SeederTest.php b/tests/SeederTest.php
index 61143e330..d78117799 100644
--- a/tests/SeederTest.php
+++ b/tests/SeederTest.php
@@ -1,4 +1,5 @@
 <?php
+declare(strict_types=1);
 
 class SeederTest extends TestCase
 {
@@ -7,7 +8,7 @@ public function tearDown(): void
         User::truncate();
     }
 
-    public function testSeed()
+    public function testSeed(): void
     {
         $seeder = new UserTableSeeder;
         $seeder->run();
@@ -16,7 +17,7 @@ public function testSeed()
         $this->assertTrue($user->seed);
     }
 
-    public function testArtisan()
+    public function testArtisan(): void
     {
         Artisan::call('db:seed');
 
diff --git a/tests/TestCase.php b/tests/TestCase.php
index f4b26be2d..5f9ec7a89 100644
--- a/tests/TestCase.php
+++ b/tests/TestCase.php
@@ -1,4 +1,7 @@
 <?php
+declare(strict_types=1);
+
+use Illuminate\Auth\Passwords\PasswordResetServiceProvider;
 
 class TestCase extends Orchestra\Testbench\TestCase
 {
@@ -13,7 +16,7 @@ protected function getApplicationProviders($app)
     {
         $providers = parent::getApplicationProviders($app);
 
-        unset($providers[array_search('Illuminate\Auth\Passwords\PasswordResetServiceProvider', $providers)]);
+        unset($providers[array_search(PasswordResetServiceProvider::class, $providers)]);
 
         return $providers;
     }
diff --git a/tests/ValidationTest.php b/tests/ValidationTest.php
index 267996420..638398866 100644
--- a/tests/ValidationTest.php
+++ b/tests/ValidationTest.php
@@ -1,4 +1,5 @@
 <?php
+declare(strict_types=1);
 
 class ValidationTest extends TestCase
 {
@@ -7,7 +8,7 @@ public function tearDown(): void
         User::truncate();
     }
 
-    public function testUnique()
+    public function testUnique(): void
     {
         $validator = Validator::make(
             ['name' => 'John Doe'],
@@ -42,7 +43,7 @@ public function testUnique()
         $this->assertFalse($validator->fails());
     }
 
-    public function testExists()
+    public function testExists(): void
     {
         $validator = Validator::make(
             ['name' => 'John Doe'],
diff --git a/tests/config/database.php b/tests/config/database.php
index 9c22bb05a..a210595fa 100644
--- a/tests/config/database.php
+++ b/tests/config/database.php
@@ -25,7 +25,7 @@
             'host'      => env('MYSQL_HOST', 'mysql'),
             'database'  => env('MYSQL_DATABASE', 'unittest'),
             'username'  => env('MYSQL_USERNAME', 'root'),
-            'password'  => '',
+            'password'  => env('MYSQL_PASSWORD', ''),
             'charset'   => 'utf8',
             'collation' => 'utf8_unicode_ci',
             'prefix'    => '',
diff --git a/tests/models/Address.php b/tests/models/Address.php
index f2f1278e1..9d094cfcd 100644
--- a/tests/models/Address.php
+++ b/tests/models/Address.php
@@ -1,13 +1,15 @@
 <?php
+declare(strict_types=1);
 
 use Jenssegers\Mongodb\Eloquent\Model as Eloquent;
+use Jenssegers\Mongodb\Relations\EmbedsMany;
 
 class Address extends Eloquent
 {
     protected $connection = 'mongodb';
     protected static $unguarded = true;
 
-    public function addresses()
+    public function addresses(): EmbedsMany
     {
         return $this->embedsMany('Address');
     }
diff --git a/tests/models/Book.php b/tests/models/Book.php
index 1cf8d22cb..27243ebcb 100644
--- a/tests/models/Book.php
+++ b/tests/models/Book.php
@@ -1,7 +1,16 @@
 <?php
+declare(strict_types=1);
 
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Jenssegers\Mongodb\Eloquent\Model as Eloquent;
 
+/**
+ * Class Book
+ *
+ * @property string $title
+ * @property string $author
+ * @property array $chapters
+ */
 class Book extends Eloquent
 {
     protected $connection = 'mongodb';
@@ -9,12 +18,12 @@ class Book extends Eloquent
     protected static $unguarded = true;
     protected $primaryKey = 'title';
 
-    public function author()
+    public function author(): BelongsTo
     {
         return $this->belongsTo('User', 'author_id');
     }
 
-    public function mysqlAuthor()
+    public function mysqlAuthor(): BelongsTo
     {
         return $this->belongsTo('MysqlUser', 'author_id');
     }
diff --git a/tests/models/Client.php b/tests/models/Client.php
index b8309deef..dc023e00a 100644
--- a/tests/models/Client.php
+++ b/tests/models/Client.php
@@ -1,5 +1,9 @@
 <?php
+declare(strict_types=1);
 
+use Illuminate\Database\Eloquent\Relations\BelongsToMany;
+use Illuminate\Database\Eloquent\Relations\HasMany;
+use Illuminate\Database\Eloquent\Relations\MorphOne;
 use Jenssegers\Mongodb\Eloquent\Model as Eloquent;
 
 class Client extends Eloquent
@@ -8,17 +12,17 @@ class Client extends Eloquent
     protected $collection = 'clients';
     protected static $unguarded = true;
 
-    public function users()
+    public function users(): BelongsToMany
     {
         return $this->belongsToMany('User');
     }
 
-    public function photo()
+    public function photo(): MorphOne
     {
         return $this->morphOne('Photo', 'imageable');
     }
 
-    public function addresses()
+    public function addresses(): HasMany
     {
         return $this->hasMany('Address', 'data.client_id', 'data.client_id');
     }
diff --git a/tests/models/Group.php b/tests/models/Group.php
index 494836ad9..369f673e8 100644
--- a/tests/models/Group.php
+++ b/tests/models/Group.php
@@ -1,5 +1,7 @@
 <?php
+declare(strict_types=1);
 
+use Illuminate\Database\Eloquent\Relations\BelongsToMany;
 use Jenssegers\Mongodb\Eloquent\Model as Eloquent;
 
 class Group extends Eloquent
@@ -8,7 +10,7 @@ class Group extends Eloquent
     protected $collection = 'groups';
     protected static $unguarded = true;
 
-    public function users()
+    public function users(): BelongsToMany
     {
         return $this->belongsToMany('User', 'users', 'groups', 'users', '_id', '_id', 'users');
     }
diff --git a/tests/models/Item.php b/tests/models/Item.php
index ac52226db..1bdc4189e 100644
--- a/tests/models/Item.php
+++ b/tests/models/Item.php
@@ -1,19 +1,27 @@
 <?php
+declare(strict_types=1);
 
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Jenssegers\Mongodb\Eloquent\Builder;
 use Jenssegers\Mongodb\Eloquent\Model as Eloquent;
 
+/**
+ * Class Item
+ *
+ * @property \Carbon\Carbon $created_at
+ */
 class Item extends Eloquent
 {
     protected $connection = 'mongodb';
     protected $collection = 'items';
     protected static $unguarded = true;
 
-    public function user()
+    public function user(): BelongsTo
     {
         return $this->belongsTo('User');
     }
 
-    public function scopeSharp($query)
+    public function scopeSharp(Builder $query)
     {
         return $query->where('type', 'sharp');
     }
diff --git a/tests/models/Location.php b/tests/models/Location.php
index aa5f36a57..3d44d5ea5 100644
--- a/tests/models/Location.php
+++ b/tests/models/Location.php
@@ -1,4 +1,5 @@
 <?php
+declare(strict_types=1);
 
 use Jenssegers\Mongodb\Eloquent\Model as Eloquent;
 
diff --git a/tests/models/MysqlBook.php b/tests/models/MysqlBook.php
index 7e755f7a6..92c287564 100644
--- a/tests/models/MysqlBook.php
+++ b/tests/models/MysqlBook.php
@@ -1,5 +1,8 @@
 <?php
+declare(strict_types=1);
 
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Schema\Blueprint;
 use Illuminate\Support\Facades\Schema;
 use Jenssegers\Mongodb\Eloquent\HybridRelations;
 
@@ -12,7 +15,7 @@ class MysqlBook extends Eloquent
     protected static $unguarded = true;
     protected $primaryKey = 'title';
 
-    public function author()
+    public function author(): BelongsTo
     {
         return $this->belongsTo('User', 'author_id');
     }
@@ -20,12 +23,13 @@ public function author()
     /**
      * Check if we need to run the schema.
      */
-    public static function executeSchema()
+    public static function executeSchema(): void
     {
+        /** @var \Illuminate\Database\Schema\MySqlBuilder $schema */
         $schema = Schema::connection('mysql');
 
         if (!$schema->hasTable('books')) {
-            Schema::connection('mysql')->create('books', function ($table) {
+            Schema::connection('mysql')->create('books', function (Blueprint $table) {
                 $table->string('title');
                 $table->string('author_id')->nullable();
                 $table->integer('mysql_user_id')->unsigned()->nullable();
diff --git a/tests/models/MysqlRole.php b/tests/models/MysqlRole.php
index e7db21d60..c721ad8c0 100644
--- a/tests/models/MysqlRole.php
+++ b/tests/models/MysqlRole.php
@@ -1,5 +1,8 @@
 <?php
+declare(strict_types=1);
 
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Schema\Blueprint;
 use Illuminate\Support\Facades\Schema;
 use Jenssegers\Mongodb\Eloquent\HybridRelations;
 
@@ -11,12 +14,12 @@ class MysqlRole extends Eloquent
     protected $table = 'roles';
     protected static $unguarded = true;
 
-    public function user()
+    public function user(): BelongsTo
     {
         return $this->belongsTo('User');
     }
 
-    public function mysqlUser()
+    public function mysqlUser(): BelongsTo
     {
         return $this->belongsTo('MysqlUser');
     }
@@ -26,10 +29,11 @@ public function mysqlUser()
      */
     public static function executeSchema()
     {
+        /** @var \Illuminate\Database\Schema\MySqlBuilder $schema */
         $schema = Schema::connection('mysql');
 
         if (!$schema->hasTable('roles')) {
-            Schema::connection('mysql')->create('roles', function ($table) {
+            Schema::connection('mysql')->create('roles', function (Blueprint $table) {
                 $table->string('type');
                 $table->string('user_id');
                 $table->timestamps();
diff --git a/tests/models/MysqlUser.php b/tests/models/MysqlUser.php
index ca15c53ff..67b1052ee 100644
--- a/tests/models/MysqlUser.php
+++ b/tests/models/MysqlUser.php
@@ -1,5 +1,9 @@
 <?php
+declare(strict_types=1);
 
+use Illuminate\Database\Eloquent\Relations\HasMany;
+use Illuminate\Database\Eloquent\Relations\HasOne;
+use Illuminate\Database\Schema\Blueprint;
 use Illuminate\Support\Facades\Schema;
 use Jenssegers\Mongodb\Eloquent\HybridRelations;
 
@@ -11,17 +15,17 @@ class MysqlUser extends Eloquent
     protected $table = 'users';
     protected static $unguarded = true;
 
-    public function books()
+    public function books(): HasMany
     {
         return $this->hasMany('Book', 'author_id');
     }
 
-    public function role()
+    public function role(): HasOne
     {
         return $this->hasOne('Role');
     }
 
-    public function mysqlBooks()
+    public function mysqlBooks(): HasMany
     {
         return $this->hasMany(MysqlBook::class);
     }
@@ -29,12 +33,13 @@ public function mysqlBooks()
     /**
      * Check if we need to run the schema.
      */
-    public static function executeSchema()
+    public static function executeSchema(): void
     {
+        /** @var \Illuminate\Database\Schema\MySqlBuilder $schema */
         $schema = Schema::connection('mysql');
 
         if (!$schema->hasTable('users')) {
-            Schema::connection('mysql')->create('users', function ($table) {
+            Schema::connection('mysql')->create('users', function (Blueprint $table) {
                 $table->increments('id');
                 $table->string('name');
                 $table->timestamps();
diff --git a/tests/models/Photo.php b/tests/models/Photo.php
index 81a5cc2de..beff63825 100644
--- a/tests/models/Photo.php
+++ b/tests/models/Photo.php
@@ -1,5 +1,7 @@
 <?php
+declare(strict_types=1);
 
+use Illuminate\Database\Eloquent\Relations\MorphTo;
 use Jenssegers\Mongodb\Eloquent\Model as Eloquent;
 
 class Photo extends Eloquent
@@ -8,7 +10,7 @@ class Photo extends Eloquent
     protected $collection = 'photos';
     protected static $unguarded = true;
 
-    public function imageable()
+    public function imageable(): MorphTo
     {
         return $this->morphTo();
     }
diff --git a/tests/models/Role.php b/tests/models/Role.php
index a59ce7e02..1e1dc9eb6 100644
--- a/tests/models/Role.php
+++ b/tests/models/Role.php
@@ -1,5 +1,7 @@
 <?php
+declare(strict_types=1);
 
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Jenssegers\Mongodb\Eloquent\Model as Eloquent;
 
 class Role extends Eloquent
@@ -8,12 +10,12 @@ class Role extends Eloquent
     protected $collection = 'roles';
     protected static $unguarded = true;
 
-    public function user()
+    public function user(): BelongsTo
     {
         return $this->belongsTo('User');
     }
 
-    public function mysqlUser()
+    public function mysqlUser(): BelongsTo
     {
         return $this->belongsTo('MysqlUser');
     }
diff --git a/tests/models/Scoped.php b/tests/models/Scoped.php
index 77a55bd55..444549916 100644
--- a/tests/models/Scoped.php
+++ b/tests/models/Scoped.php
@@ -1,4 +1,5 @@
 <?php
+declare(strict_types=1);
 
 use Jenssegers\Mongodb\Eloquent\Model as Eloquent;
 use Jenssegers\Mongodb\Eloquent\Builder;
diff --git a/tests/models/Soft.php b/tests/models/Soft.php
index 783cf0289..f7c7b5cd8 100644
--- a/tests/models/Soft.php
+++ b/tests/models/Soft.php
@@ -1,8 +1,14 @@
 <?php
+declare(strict_types=1);
 
 use Jenssegers\Mongodb\Eloquent\Model as Eloquent;
 use Jenssegers\Mongodb\Eloquent\SoftDeletes;
 
+/**
+ * Class Soft
+ *
+ * @property \Carbon\Carbon $deleted_at
+ */
 class Soft extends Eloquent
 {
     use SoftDeletes;
diff --git a/tests/models/User.php b/tests/models/User.php
index d233c3f32..7de25e924 100644
--- a/tests/models/User.php
+++ b/tests/models/User.php
@@ -1,5 +1,7 @@
 <?php
+declare(strict_types=1);
 
+use Illuminate\Notifications\Notifiable;
 use Jenssegers\Mongodb\Eloquent\Model as Eloquent;
 use Jenssegers\Mongodb\Eloquent\HybridRelations;
 use Illuminate\Auth\Authenticatable;
@@ -7,9 +9,20 @@
 use Illuminate\Contracts\Auth\Authenticatable as AuthenticatableContract;
 use Illuminate\Contracts\Auth\CanResetPassword as CanResetPasswordContract;
 
+/**
+ * Class User
+ *
+ * @property string $_id
+ * @property string $name
+ * @property string $title
+ * @property int $age
+ * @property \Carbon\Carbon $birthday
+ * @property \Carbon\Carbon $created_at
+ * @property \Carbon\Carbon $updated_at
+ */
 class User extends Eloquent implements AuthenticatableContract, CanResetPasswordContract
 {
-    use Authenticatable, CanResetPassword, HybridRelations;
+    use Authenticatable, CanResetPassword, HybridRelations, Notifiable;
 
     protected $connection = 'mongodb';
     protected $dates = ['birthday', 'entry.date'];