diff --git a/src/Serializer/AbstractItemNormalizer.php b/src/Serializer/AbstractItemNormalizer.php
index e8695e1e79..226d6853fa 100644
--- a/src/Serializer/AbstractItemNormalizer.php
+++ b/src/Serializer/AbstractItemNormalizer.php
@@ -652,7 +652,7 @@ protected function denormalizeObjectCollection(string $attribute, ApiProperty $p
                 $collectionKeyType = $type->getCollectionKeyType();
 
                 while ($collectionKeyType instanceof WrappingTypeInterface) {
-                    $collectionKeyType = $type->getWrappedType();
+                    $collectionKeyType = $collectionKeyType->getWrappedType();
                 }
 
                 if (!$collectionKeyType->accepts($index)) {
diff --git a/src/Serializer/Tests/AbstractItemNormalizerTest.php b/src/Serializer/Tests/AbstractItemNormalizerTest.php
index 3a44cbd322..3a1b7e1273 100644
--- a/src/Serializer/Tests/AbstractItemNormalizerTest.php
+++ b/src/Serializer/Tests/AbstractItemNormalizerTest.php
@@ -1936,6 +1936,46 @@ public function testDenormalizeCollectionDecodedFromXmlWithOneChild(): void
         $normalizer->denormalize($data, Dummy::class, 'xml');
     }
 
+    public function testDenormalizeCollectionWithTemplateKeyType(): void
+    {
+        $data = [
+            'relatedDummies' => [
+                ['name' => 'foo'],
+            ],
+        ];
+
+        $relatedDummy = new RelatedDummy();
+        $relatedDummy->setName('foo');
+
+        $propertyNameCollectionFactoryProphecy = $this->prophesize(PropertyNameCollectionFactoryInterface::class);
+        $propertyNameCollectionFactoryProphecy->create(Dummy::class, Argument::type('array'))->willReturn(new PropertyNameCollection(['relatedDummies']));
+
+        $relatedDummiesType = Type::array(Type::object(RelatedDummy::class), Type::template('TKey', Type::arrayKey()));
+
+        $propertyMetadataFactoryProphecy = $this->prophesize(PropertyMetadataFactoryInterface::class);
+        $propertyMetadataFactoryProphecy->create(Dummy::class, 'relatedDummies', Argument::type('array'))->willReturn((new ApiProperty())->withNativeType($relatedDummiesType)->withReadable(false)->withWritable(true)->withReadableLink(false)->withWritableLink(true));
+
+        $iriConverterProphecy = $this->prophesize(IriConverterInterface::class);
+
+        $propertyAccessorProphecy = $this->prophesize(PropertyAccessorInterface::class);
+        $propertyAccessorProphecy->setValue(Argument::type(Dummy::class), 'relatedDummies', [$relatedDummy])->shouldBeCalled();
+
+        $resourceClassResolverProphecy = $this->prophesize(ResourceClassResolverInterface::class);
+        $resourceClassResolverProphecy->getResourceClass(null, Dummy::class)->willReturn(Dummy::class);
+        $resourceClassResolverProphecy->getResourceClass(null, RelatedDummy::class)->willReturn(RelatedDummy::class);
+        $resourceClassResolverProphecy->isResourceClass(RelatedDummy::class)->willReturn(true);
+        $resourceClassResolverProphecy->isResourceClass(Dummy::class)->willReturn(true);
+
+        $serializerProphecy = $this->prophesize(SerializerInterface::class);
+        $serializerProphecy->willImplement(DenormalizerInterface::class);
+        $serializerProphecy->denormalize(['name' => 'foo'], RelatedDummy::class, null, Argument::type('array'))->willReturn($relatedDummy);
+
+        $normalizer = new class($propertyNameCollectionFactoryProphecy->reveal(), $propertyMetadataFactoryProphecy->reveal(), $iriConverterProphecy->reveal(), $resourceClassResolverProphecy->reveal(), $propertyAccessorProphecy->reveal(), null, null, [], null, null) extends AbstractItemNormalizer {};
+        $normalizer->setSerializer($serializerProphecy->reveal());
+
+        $normalizer->denormalize($data, Dummy::class);
+    }
+
     public function testDenormalizePopulatingNonCloneableObject(): void
     {
         $dummy = new NonCloneableDummy();