diff --git a/lib/Doctrine/ORM/Internal/Hydration/ObjectHydrator.php b/lib/Doctrine/ORM/Internal/Hydration/ObjectHydrator.php
index 8c675509cf7..581dce6b77c 100644
--- a/lib/Doctrine/ORM/Internal/Hydration/ObjectHydrator.php
+++ b/lib/Doctrine/ORM/Internal/Hydration/ObjectHydrator.php
@@ -14,6 +14,7 @@
 
 use function array_fill_keys;
 use function array_keys;
+use function array_map;
 use function count;
 use function is_array;
 use function key;
@@ -284,13 +285,17 @@ private function getEntityFromIdentityMap(string $className, array $data)
         $class = $this->_metadataCache[$className];
 
         if ($class->isIdentifierComposite) {
-            $idHash = '';
-
-            foreach ($class->identifier as $fieldName) {
-                $idHash .= ' ' . (isset($class->associationMappings[$fieldName])
-                    ? $data[$class->associationMappings[$fieldName]['joinColumns'][0]['name']]
-                    : $data[$fieldName]);
-            }
+            $idHash = UnitOfWork::getIdHashByIdentifier(
+                array_map(
+                    /** @return mixed */
+                    static function (string $fieldName) use ($data, $class) {
+                        return isset($class->associationMappings[$fieldName])
+                            ? $data[$class->associationMappings[$fieldName]['joinColumns'][0]['name']]
+                            : $data[$fieldName];
+                    },
+                    $class->identifier
+                )
+            );
 
             return $this->_uow->tryGetByIdHash(ltrim($idHash), $class->rootEntityName);
         } elseif (isset($class->associationMappings[$class->identifier[0]])) {
diff --git a/lib/Doctrine/ORM/Persisters/Entity/BasicEntityPersister.php b/lib/Doctrine/ORM/Persisters/Entity/BasicEntityPersister.php
index 0b655254dfd..efcce4b3c4f 100644
--- a/lib/Doctrine/ORM/Persisters/Entity/BasicEntityPersister.php
+++ b/lib/Doctrine/ORM/Persisters/Entity/BasicEntityPersister.php
@@ -271,6 +271,10 @@ public function executeInserts()
                 $paramIndex = 1;
 
                 foreach ($insertData[$tableName] as $column => $value) {
+                    if ($value instanceof BackedEnum) {
+                        $value = $value->value;
+                    }
+
                     $stmt->bindValue($paramIndex++, $value, $this->columnTypes[$column]);
                 }
             }
diff --git a/lib/Doctrine/ORM/UnitOfWork.php b/lib/Doctrine/ORM/UnitOfWork.php
index a859ccc46b1..568420258ae 100644
--- a/lib/Doctrine/ORM/UnitOfWork.php
+++ b/lib/Doctrine/ORM/UnitOfWork.php
@@ -1566,14 +1566,8 @@ public function isEntityScheduled($entity)
     public function addToIdentityMap($entity)
     {
         $classMetadata = $this->em->getClassMetadata(get_class($entity));
-        $identifier    = $this->entityIdentifiers[spl_object_id($entity)];
-
-        if (empty($identifier) || in_array(null, $identifier, true)) {
-            throw ORMInvalidArgumentException::entityWithoutIdentity($classMetadata->name, $entity);
-        }
-
-        $idHash    = implode(' ', $identifier);
-        $className = $classMetadata->rootEntityName;
+        $idHash        = $this->getIdHashByEntity($entity);
+        $className     = $classMetadata->rootEntityName;
 
         if (isset($this->identityMap[$className][$idHash])) {
             return false;
@@ -1584,6 +1578,50 @@ public function addToIdentityMap($entity)
         return true;
     }
 
+    /**
+     * Gets the id hash of an entity by its identifier.
+     *
+     * @param array<string|int, mixed> $identifier The identifier of an entity
+     *
+     * @return string The entity id hash.
+     */
+    final public static function getIdHashByIdentifier(array $identifier): string
+    {
+        return implode(
+            ' ',
+            array_map(
+                static function ($value) {
+                    if ($value instanceof BackedEnum) {
+                        return $value->value;
+                    }
+
+                    return $value;
+                },
+                $identifier
+            )
+        );
+    }
+
+    /**
+     * Gets the id hash of an entity.
+     *
+     * @param object $entity The entity managed by Unit Of Work
+     *
+     * @return string The entity id hash.
+     */
+    public function getIdHashByEntity($entity): string
+    {
+        $identifier = $this->entityIdentifiers[spl_object_id($entity)];
+
+        if (empty($identifier) || in_array(null, $identifier, true)) {
+            $classMetadata = $this->em->getClassMetadata(get_class($entity));
+
+            throw ORMInvalidArgumentException::entityWithoutIdentity($classMetadata->name, $entity);
+        }
+
+        return self::getIdHashByIdentifier($identifier);
+    }
+
     /**
      * Gets the state of an entity with regard to the current unit of work.
      *
@@ -1686,7 +1724,7 @@ public function removeFromIdentityMap($entity)
     {
         $oid           = spl_object_id($entity);
         $classMetadata = $this->em->getClassMetadata(get_class($entity));
-        $idHash        = implode(' ', $this->entityIdentifiers[$oid]);
+        $idHash        = self::getIdHashByIdentifier($this->entityIdentifiers[$oid]);
 
         if ($idHash === '') {
             throw ORMInvalidArgumentException::entityHasNoIdentity($entity, 'remove from identity map');
@@ -1756,7 +1794,7 @@ public function isInIdentityMap($entity)
         }
 
         $classMetadata = $this->em->getClassMetadata(get_class($entity));
-        $idHash        = implode(' ', $this->entityIdentifiers[$oid]);
+        $idHash        = self::getIdHashByIdentifier($this->entityIdentifiers[$oid]);
 
         return isset($this->identityMap[$classMetadata->rootEntityName][$idHash]);
     }
@@ -2713,7 +2751,7 @@ public function createEntity($className, array $data, &$hints = [])
         $class = $this->em->getClassMetadata($className);
 
         $id     = $this->identifierFlattener->flattenIdentifier($class, $data);
-        $idHash = implode(' ', $id);
+        $idHash = self::getIdHashByIdentifier($id);
 
         if (isset($this->identityMap[$class->rootEntityName][$idHash])) {
             $entity = $this->identityMap[$class->rootEntityName][$idHash];
@@ -2872,7 +2910,7 @@ public function createEntity($className, array $data, &$hints = [])
                     // Check identity map first
                     // FIXME: Can break easily with composite keys if join column values are in
                     //        wrong order. The correct order is the one in ClassMetadata#identifier.
-                    $relatedIdHash = implode(' ', $associatedId);
+                    $relatedIdHash = self::getIdHashByIdentifier($associatedId);
 
                     switch (true) {
                         case isset($this->identityMap[$targetClass->rootEntityName][$relatedIdHash]):
@@ -3157,7 +3195,7 @@ public function getSingleIdentifierValue($entity)
      */
     public function tryGetById($id, $rootClassName)
     {
-        $idHash = implode(' ', (array) $id);
+        $idHash = self::getIdHashByIdentifier((array) $id);
 
         return $this->identityMap[$rootClassName][$idHash] ?? false;
     }
@@ -3539,7 +3577,7 @@ private function isIdentifierEquals($entity1, $entity2): bool
         $id1 = $this->entityIdentifiers[$oid1] ?? $this->identifierFlattener->flattenIdentifier($class, $class->getIdentifierValues($entity1));
         $id2 = $this->entityIdentifiers[$oid2] ?? $this->identifierFlattener->flattenIdentifier($class, $class->getIdentifierValues($entity2));
 
-        return $id1 === $id2 || implode(' ', $id1) === implode(' ', $id2);
+        return $id1 === $id2 || self::getIdHashByIdentifier($id1) === self::getIdHashByIdentifier($id2);
     }
 
     /** @throws ORMInvalidArgumentException */
diff --git a/tests/Doctrine/Tests/Models/GH10334/GH10334Foo.php b/tests/Doctrine/Tests/Models/GH10334/GH10334Foo.php
new file mode 100644
index 00000000000..1918d32f7b3
--- /dev/null
+++ b/tests/Doctrine/Tests/Models/GH10334/GH10334Foo.php
@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\Models\GH10334;
+
+use Doctrine\ORM\Mapping\Column;
+use Doctrine\ORM\Mapping\Entity;
+use Doctrine\ORM\Mapping\GeneratedValue;
+use Doctrine\ORM\Mapping\Id;
+use Doctrine\ORM\Mapping\JoinColumn;
+use Doctrine\ORM\Mapping\ManyToOne;
+
+/**
+ * @Entity
+ */
+class GH10334Foo
+{
+    /**
+     * @var GH10334FooCollection
+     * @Id
+     * @ManyToOne(targetEntity="GH10334FooCollection", inversedBy="foos")
+     * @JoinColumn(name="foo_collection_id", referencedColumnName="id", nullable = false)
+     * @GeneratedValue
+     */
+    protected $collection;
+
+    /**
+     * @var GH10334ProductTypeId
+     * @Id
+     * @Column(type="string", enumType="Doctrine\Tests\Models\GH10334\GH10334ProductTypeId")
+     */
+    protected $productTypeId;
+
+    public function __construct(GH10334FooCollection $collection, GH10334ProductTypeId $productTypeId)
+    {
+        $this->collection    = $collection;
+        $this->productTypeId = $productTypeId;
+    }
+}
diff --git a/tests/Doctrine/Tests/Models/GH10334/GH10334FooCollection.php b/tests/Doctrine/Tests/Models/GH10334/GH10334FooCollection.php
new file mode 100644
index 00000000000..749fd899c20
--- /dev/null
+++ b/tests/Doctrine/Tests/Models/GH10334/GH10334FooCollection.php
@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\Models\GH10334;
+
+use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
+use Doctrine\ORM\Mapping\Column;
+use Doctrine\ORM\Mapping\Entity;
+use Doctrine\ORM\Mapping\GeneratedValue;
+use Doctrine\ORM\Mapping\Id;
+use Doctrine\ORM\Mapping\OneToMany;
+
+/**
+ * @Entity
+ */
+class GH10334FooCollection
+{
+    /**
+     * @var int
+     * @Id
+     * @Column(type="integer")
+     * @GeneratedValue
+     */
+    protected $id;
+
+    /**
+     * @OneToMany(targetEntity="GH10334Foo", mappedBy="collection", cascade={"persist", "remove"})
+     * @var Collection<GH10334Foo> $foos
+     */
+    private $foos;
+
+    public function __construct()
+    {
+        $this->foos = new ArrayCollection();
+    }
+
+    /**
+     * @return Collection<GH10334Foo>
+     */
+    public function getFoos(): Collection
+    {
+        return $this->foos;
+    }
+}
diff --git a/tests/Doctrine/Tests/Models/GH10334/GH10334Product.php b/tests/Doctrine/Tests/Models/GH10334/GH10334Product.php
new file mode 100644
index 00000000000..28c5c39c5a6
--- /dev/null
+++ b/tests/Doctrine/Tests/Models/GH10334/GH10334Product.php
@@ -0,0 +1,55 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\Models\GH10334;
+
+use Doctrine\ORM\Mapping\Column;
+use Doctrine\ORM\Mapping\Entity;
+use Doctrine\ORM\Mapping\GeneratedValue;
+use Doctrine\ORM\Mapping\Id;
+use Doctrine\ORM\Mapping\JoinColumn;
+use Doctrine\ORM\Mapping\ManyToOne;
+
+/**
+ * @Entity
+ */
+class GH10334Product
+{
+    /**
+     * @var int
+     * @Id
+     * @Column(name="product_id", type="integer")
+     * @GeneratedValue()
+     */
+    protected $id;
+
+    /**
+     * @var string
+     * @Column(name="name", type="string")
+     */
+    private $name;
+
+    /**
+     * @var GH10334ProductType $productType
+     * @ManyToOne(targetEntity="GH10334ProductType", inversedBy="products")
+     * @JoinColumn(name="product_type_id", referencedColumnName="id", nullable = false)
+     */
+    private $productType;
+
+    public function __construct(string $name, GH10334ProductType $productType)
+    {
+        $this->name        = $name;
+        $this->productType = $productType;
+    }
+
+    public function getProductType(): GH10334ProductType
+    {
+        return $this->productType;
+    }
+
+    public function setProductType(GH10334ProductType $productType): void
+    {
+        $this->productType = $productType;
+    }
+}
diff --git a/tests/Doctrine/Tests/Models/GH10334/GH10334ProductType.php b/tests/Doctrine/Tests/Models/GH10334/GH10334ProductType.php
new file mode 100644
index 00000000000..0e26e956563
--- /dev/null
+++ b/tests/Doctrine/Tests/Models/GH10334/GH10334ProductType.php
@@ -0,0 +1,55 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\Models\GH10334;
+
+use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
+use Doctrine\ORM\Mapping\Column;
+use Doctrine\ORM\Mapping\Entity;
+use Doctrine\ORM\Mapping\Id;
+use Doctrine\ORM\Mapping\OneToMany;
+
+/**
+ * @Entity
+ */
+class GH10334ProductType
+{
+    /**
+     * @var GH10334ProductTypeId
+     * @Id
+     * @Column(type="string", enumType="Doctrine\Tests\Models\GH10334\GH10334ProductTypeId")
+     */
+    protected $id;
+
+    /**
+     * @var float
+     * @Column(type="float")
+     */
+    private $value;
+
+    /**
+     * @OneToMany(targetEntity="GH10334Product", mappedBy="productType", cascade={"persist", "remove"})
+     * @var Collection $products
+     */
+    private $products;
+
+    public function __construct(GH10334ProductTypeId $id, float $value)
+    {
+        $this->id       = $id;
+        $this->value    = $value;
+        $this->products = new ArrayCollection();
+    }
+
+    public function getId(): GH10334ProductTypeId
+    {
+        return $this->id;
+    }
+
+    public function addProduct(GH10334Product $product): void
+    {
+        $product->setProductType($this);
+        $this->products->add($product);
+    }
+}
diff --git a/tests/Doctrine/Tests/Models/GH10334/GH10334ProductTypeId.php b/tests/Doctrine/Tests/Models/GH10334/GH10334ProductTypeId.php
new file mode 100644
index 00000000000..92314e4ba94
--- /dev/null
+++ b/tests/Doctrine/Tests/Models/GH10334/GH10334ProductTypeId.php
@@ -0,0 +1,11 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\Models\GH10334;
+
+enum GH10334ProductTypeId: string
+{
+    case Jean  = 'jean';
+    case Short = 'short';
+}
diff --git a/tests/Doctrine/Tests/ORM/Functional/Ticket/GH10334Test.php b/tests/Doctrine/Tests/ORM/Functional/Ticket/GH10334Test.php
new file mode 100644
index 00000000000..6a5d1440332
--- /dev/null
+++ b/tests/Doctrine/Tests/ORM/Functional/Ticket/GH10334Test.php
@@ -0,0 +1,78 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\ORM\Functional\Ticket;
+
+use Doctrine\Tests\Models\GH10334\GH10334Foo;
+use Doctrine\Tests\Models\GH10334\GH10334FooCollection;
+use Doctrine\Tests\Models\GH10334\GH10334Product;
+use Doctrine\Tests\Models\GH10334\GH10334ProductType;
+use Doctrine\Tests\Models\GH10334\GH10334ProductTypeId;
+use Doctrine\Tests\OrmFunctionalTestCase;
+
+/**
+ * @group GH10334Test
+ * @requires PHP 8.1
+ */
+class GH10334Test extends OrmFunctionalTestCase
+{
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->setUpEntitySchema([GH10334FooCollection::class, GH10334Foo::class, GH10334ProductType::class, GH10334Product::class]);
+    }
+
+    public function testTicket(): void
+    {
+        $collection = new GH10334FooCollection();
+        $foo        = new GH10334Foo($collection, GH10334ProductTypeId::Jean);
+        $foo2       = new GH10334Foo($collection, GH10334ProductTypeId::Short);
+
+        $this->_em->persist($collection);
+        $this->_em->persist($foo);
+        $this->_em->persist($foo2);
+
+        $this->_em->flush();
+        $this->_em->clear();
+
+        $result = $this->_em
+            ->getRepository(GH10334FooCollection::class)
+            ->createQueryBuilder('collection')
+            ->leftJoin('collection.foos', 'foo')->addSelect('foo')
+            ->getQuery()
+            ->getResult();
+
+        $this->_em
+            ->getRepository(GH10334FooCollection::class)
+            ->createQueryBuilder('collection')
+            ->leftJoin('collection.foos', 'foo')->addSelect('foo')
+            ->getQuery()
+            ->getResult();
+
+        $this->assertCount(1, $result);
+        $this->assertCount(2, $result[0]->getFoos());
+    }
+
+    public function testGetChildWithBackedEnumId(): void
+    {
+        $jean    = new GH10334ProductType(GH10334ProductTypeId::Jean, 23.5);
+        $short   = new GH10334ProductType(GH10334ProductTypeId::Short, 45.2);
+        $product = new GH10334Product('Extra Large Blue', $jean);
+
+        $jean->addProduct($product);
+
+        $this->_em->persist($jean);
+        $this->_em->persist($short);
+        $this->_em->persist($product);
+
+        $this->_em->flush();
+        $this->_em->clear();
+
+        $entity = $this->_em->find(GH10334Product::class, 1);
+
+        self::assertNotNull($entity);
+        self::assertSame($entity->getProductType()->getId(), GH10334ProductTypeId::Jean);
+    }
+}