diff --git a/grumphp.yml b/grumphp.yml
index eda5fcd33..cccee9beb 100644
--- a/grumphp.yml
+++ b/grumphp.yml
@@ -40,7 +40,7 @@ grumphp:
     check:
       tasks:
         - phpcsfixer
-        # - phpstan
+        - phpstan
         - twigcs
         # - xlifflint # TODO: Re-implement
         - yamllint
diff --git a/src/Controller/App/MapperController.php b/src/Controller/App/MapperController.php
index 4aae345af..2046ac8c4 100644
--- a/src/Controller/App/MapperController.php
+++ b/src/Controller/App/MapperController.php
@@ -6,6 +6,7 @@
 use App\Entity\Note;
 use App\Entity\Region;
 use App\Entity\Template;
+use App\Entity\User;
 use App\Entity\Welcome;
 use App\Service\RegionsProvider;
 use App\Service\TemplatesProvider;
@@ -22,6 +23,9 @@
 class MapperController extends AbstractController
 {
     private Mapper $mapper;
+
+    private ?User $user;
+
     /** @var Template[] */
     private array $templates;
 
@@ -39,6 +43,7 @@ public function index(Request $request, string $regionKey, int $id, ?string $con
     {
         $region = $this->provider->getRegion($continent, $regionKey);
 
+        $this->user = $this->getUser(); // @phpstan-ignore assign.propertyType
         $this->mapper = $this->entityManager->find(Mapper::class, $id);
 
         $mapperRegions = array_map(fn (Region $region) => $region->getId(), $this->mapper->getRegion()->toArray());
@@ -102,7 +107,7 @@ private function updateWelcomeDate(bool $state): void
 
         if (true === $state) {
             $welcome->setDate(new \DateTime());
-            $welcome->setUser($this->getUser());
+            $welcome->setUser($this->user);
 
             $this->entityManager->persist($welcome);
         } else {
@@ -119,7 +124,7 @@ private function updateWelcomeReply(bool $state): void
             $welcome = new Welcome();
             $welcome->setMapper($this->mapper);
             $welcome->setDate(new \DateTime());
-            $welcome->setUser($this->getUser());
+            $welcome->setUser($this->user);
         }
         $welcome->setReply($state ? new \DateTime() : null);
 
@@ -164,7 +169,7 @@ private function note(Request $request): FormInterface
     {
         $note = new Note();
         $note->setMapper($this->mapper);
-        $note->setAuthor($this->getUser());
+        $note->setAuthor($this->user);
 
         $form = $this->createFormBuilder($note)
             ->add('text', TextareaType::class, ['label' => 'Note'])
diff --git a/src/Entity/Mapper.php b/src/Entity/Mapper.php
index e876a0cb3..181efacce 100644
--- a/src/Entity/Mapper.php
+++ b/src/Entity/Mapper.php
@@ -26,18 +26,21 @@ class Mapper
     #[ORM\Column(type: 'string', length: 255)]
     private ?string $status;
 
+    /** @var Collection<int,Changeset> */
     #[ORM\OneToMany(targetEntity: Changeset::class, mappedBy: 'mapper', orphanRemoval: true)]
     private Collection $changesets;
 
     #[ORM\Column(type: 'text', nullable: true)]
     private ?string $image;
 
+    /** @var Collection<int,Note> */
     #[ORM\OneToMany(targetEntity: Note::class, mappedBy: 'mapper', orphanRemoval: true)]
     private Collection $notes;
 
     #[ORM\OneToOne(targetEntity: Welcome::class, mappedBy: 'mapper', cascade: ['persist'])]
     private ?Welcome $welcome;
 
+    /** @var Collection<int,Region> */
     #[ORM\ManyToMany(targetEntity: Region::class, inversedBy: 'mappers')]
     private Collection $region;
 
@@ -109,7 +112,7 @@ public function setStatus(string $status): self
     }
 
     /**
-     * @return Collection|Changeset[]
+     * @return Collection<int,Changeset>
      */
     public function getChangesets(): Collection
     {
@@ -149,7 +152,7 @@ public function setImage(?string $image): self
     }
 
     /**
-     * @return Collection|Note[]
+     * @return Collection<int,Note>
      */
     public function getNotes(): Collection
     {
diff --git a/src/Entity/Region.php b/src/Entity/Region.php
index 166fab40f..d061de642 100644
--- a/src/Entity/Region.php
+++ b/src/Entity/Region.php
@@ -17,6 +17,7 @@ class Region
     #[ORM\Column(type: 'datetime')]
     private \DateTime $lastUpdate;
 
+    /** @var Collection<int,Mapper> */
     #[ORM\ManyToMany(targetEntity: Mapper::class, mappedBy: 'region')]
     private Collection $mappers;
 
diff --git a/src/Security/OpenStreetMapAuthenticator.php b/src/Security/OpenStreetMapAuthenticator.php
index dd8f5c878..89a57e530 100644
--- a/src/Security/OpenStreetMapAuthenticator.php
+++ b/src/Security/OpenStreetMapAuthenticator.php
@@ -44,9 +44,9 @@ public function authenticate(Request $request): Passport
                 $openstreetmapUser = $client->fetchUserFromToken($accessToken);
 
                 $user = $this->entityManager->getRepository(User::class)->find($openstreetmapUser->getId());
-                if (null === $user) {
+                if (null === $user && null !== $openstreetmapUser->getId()) {
                     $user = new User();
-                    $user->setId($openstreetmapUser->getId());
+                    $user->setId((int) $openstreetmapUser->getId());
                 }
 
                 $user->setDisplayName($openstreetmapUser->getDisplayName());