diff --git a/lib/Doctrine/ORM/UnitOfWork.php b/lib/Doctrine/ORM/UnitOfWork.php
index c79afd084ee..289f83fb2c5 100644
--- a/lib/Doctrine/ORM/UnitOfWork.php
+++ b/lib/Doctrine/ORM/UnitOfWork.php
@@ -104,6 +104,15 @@ class UnitOfWork implements PropertyChangedListener
      */
     private $identityMap = [];
 
+    /**
+     * Associate entities with OIDs to ensure the GC won't recycle a managed entity
+     *
+     * DDC-2332 / #3037
+     *
+     * @var array
+     */
+    private $oidMap = array();
+
     /**
      * Map of all identifiers of managed entities.
      * Keys are object ids (spl_object_hash).
@@ -1498,7 +1507,8 @@ public function isEntityScheduled($entity)
     public function addToIdentityMap($entity)
     {
         $classMetadata = $this->em->getClassMetadata(get_class($entity));
-        $identifier    = $this->entityIdentifiers[spl_object_hash($entity)];
+        $oid           = spl_object_hash($entity);
+        $identifier    = $this->entityIdentifiers[$oid];
 
         if (empty($identifier) || in_array(null, $identifier, true)) {
             throw ORMInvalidArgumentException::entityWithoutIdentity($classMetadata->name, $entity);
@@ -1507,6 +1517,7 @@ public function addToIdentityMap($entity)
         $idHash    = implode(' ', $identifier);
         $className = $classMetadata->rootEntityName;
 
+        $this->oidMap[$oid] = $entity;
         if (isset($this->identityMap[$className][$idHash])) {
             return false;
         }
@@ -1622,6 +1633,7 @@ public function removeFromIdentityMap($entity)
 
         $className = $classMetadata->rootEntityName;
 
+        unset($this->oidMap[$oid]);
         if (isset($this->identityMap[$className][$idHash])) {
             unset($this->identityMap[$className][$idHash]);
             unset($this->readOnlyObjects[$oid]);
@@ -2482,6 +2494,7 @@ public function clear($entityName = null)
     {
         if ($entityName === null) {
             $this->identityMap =
+            $this->oidMap =
             $this->entityIdentifiers =
             $this->originalEntityData =
             $this->entityChangeSets =
@@ -2656,6 +2669,7 @@ public function createEntity($className, array $data, &$hints = [])
             $this->entityStates[$oid]       = self::STATE_MANAGED;
             $this->originalEntityData[$oid] = $data;
 
+            $this->oidMap[$oid] = $entity;
             $this->identityMap[$class->rootEntityName][$idHash] = $entity;
 
             if ($entity instanceof NotifyPropertyChanged) {
@@ -2806,6 +2820,7 @@ public function createEntity($className, array $data, &$hints = [])
                             // PERF: Inlined & optimized code from UnitOfWork#registerManaged()
                             $newValueOid = spl_object_hash($newValue);
                             $this->entityIdentifiers[$newValueOid] = $associatedId;
+                            $this->oidMap[$newValueOid] = $newValue;
                             $this->identityMap[$targetClass->rootEntityName][$relatedIdHash] = $newValue;
 
                             if (
diff --git a/tests/Doctrine/Tests/ORM/Functional/IdentityMapTest.php b/tests/Doctrine/Tests/ORM/Functional/IdentityMapTest.php
index 15929ae270d..ef7748ddb5a 100644
--- a/tests/Doctrine/Tests/ORM/Functional/IdentityMapTest.php
+++ b/tests/Doctrine/Tests/ORM/Functional/IdentityMapTest.php
@@ -4,6 +4,7 @@
 
 use Doctrine\ORM\Query;
 use Doctrine\Tests\Models\CMS\CmsAddress;
+use Doctrine\Tests\Models\CMS\CmsArticle;
 use Doctrine\Tests\Models\CMS\CmsPhonenumber;
 use Doctrine\Tests\Models\CMS\CmsUser;
 use Doctrine\Tests\OrmFunctionalTestCase;
@@ -254,5 +255,50 @@ public function testCollectionValuedAssociationIdentityMapBehaviorWithRefresh()
         // Now the collection should be refreshed with correct count
         $this->assertEquals(4, count($user2->getPhonenumbers()));
     }
+
+    /**
+     * @group HashCollision
+     */
+    public function testHashCollision() {
+        $user = new CmsUser();
+        $user->username = "Test";
+        $user->name = "Test";
+        $this->_em->persist($user);
+        $this->_em->flush();
+
+        $articles = [];
+        for ($i = 0; $i < 100; $i++) {
+            $article = new CmsArticle();
+            $article->topic = "Test";
+            $article->text = "Test";
+            $article->setAuthor($this->_em->merge($user));
+            $this->_em->persist($article);
+            $this->_em->flush();
+            $this->_em->clear();
+            $articles [] = $article;
+        }
+
+        $user = $this->_em->merge($user);
+        foreach ($articles as $article) {
+            $article = $this->_em->merge($article);
+            $article->setAuthor($user);
+        }
+
+        unset($article);
+        gc_collect_cycles();
+
+        $keep = [];
+        for ($x = 0; $x < 1000; $x++) {
+            $keep[] = $article = new CmsArticle();
+
+            $article->topic = "Test";
+            $article->text = "Test";
+            $article->setAuthor($this->_em->merge($user));
+
+            $this->_em->persist($article);
+            $this->_em->flush();
+            $this->assertNotNull($article->id, "Article wasn't persisted on iteration $x");
+        }
+    }
 }