diff --git a/src/Illuminate/Database/Eloquent/Relations/HasOneOrMany.php b/src/Illuminate/Database/Eloquent/Relations/HasOneOrMany.php
index 54850fa33b24..20b2b4f7b76f 100755
--- a/src/Illuminate/Database/Eloquent/Relations/HasOneOrMany.php
+++ b/src/Illuminate/Database/Eloquent/Relations/HasOneOrMany.php
@@ -316,7 +316,7 @@ protected function setForeignAttributesForCreate(Model $model)
      */
     public function update(array $attributes)
     {
-        if ($this->related->usesTimestamps()) {
+        if ($this->related->usesTimestamps() && ! is_null($this->relatedUpdatedAt())) {
             $attributes[$this->relatedUpdatedAt()] = $this->related->freshTimestampString();
         }
 
diff --git a/tests/Database/DatabaseEloquentHasManyTest.php b/tests/Database/DatabaseEloquentHasManyTest.php
index 48fda761340a..038fe47b0c4b 100755
--- a/tests/Database/DatabaseEloquentHasManyTest.php
+++ b/tests/Database/DatabaseEloquentHasManyTest.php
@@ -173,6 +173,16 @@ public function testUpdateMethodUpdatesModelsWithTimestamps()
         $this->assertEquals('results', $relation->update(['foo' => 'bar']));
     }
 
+    public function testUpdateMethodUpdatesModelsWithNullUpdatedAt()
+    {
+        $relation = $this->getRelation();
+        $relation->getRelated()->shouldReceive('usesTimestamps')->once()->andReturn(true);
+        $relation->getRelated()->shouldReceive('getUpdatedAtColumn')->andReturn(null);
+        $relation->getQuery()->shouldReceive('update')->once()->with(['foo' => 'bar'])->andReturn('results');
+
+        $this->assertEquals('results', $relation->update(['foo' => 'bar']));
+    }
+
     public function testRelationIsProperlyInitialized()
     {
         $relation = $this->getRelation();
diff --git a/tests/Database/DatabaseEloquentHasOneTest.php b/tests/Database/DatabaseEloquentHasOneTest.php
index 44910f720bbe..9e8f7ee4fce8 100755
--- a/tests/Database/DatabaseEloquentHasOneTest.php
+++ b/tests/Database/DatabaseEloquentHasOneTest.php
@@ -136,6 +136,16 @@ public function testUpdateMethodUpdatesModelsWithTimestamps()
         $this->assertEquals('results', $relation->update(['foo' => 'bar']));
     }
 
+    public function testUpdateMethodUpdatesModelsWithNullUpdatedAt()
+    {
+        $relation = $this->getRelation();
+        $relation->getRelated()->shouldReceive('usesTimestamps')->once()->andReturn(true);
+        $relation->getRelated()->shouldReceive('getUpdatedAtColumn')->andReturn(null);
+        $relation->getQuery()->shouldReceive('update')->once()->with(['foo' => 'bar'])->andReturn('results');
+
+        $this->assertEquals('results', $relation->update(['foo' => 'bar']));
+    }
+
     public function testRelationIsProperlyInitialized()
     {
         $relation = $this->getRelation();