diff --git a/lib/Doctrine/ORM/UnitOfWork.php b/lib/Doctrine/ORM/UnitOfWork.php
index f35c20eff..d0f5bc022 100644
--- a/lib/Doctrine/ORM/UnitOfWork.php
+++ b/lib/Doctrine/ORM/UnitOfWork.php
@@ -462,6 +462,7 @@ class UnitOfWork implements PropertyChangedListener
                         // A PersistentCollection was de-referenced, so delete it.
                         if  ( ! in_array($orgValue, $this->collectionDeletions, true)) {
                             $this->collectionDeletions[] = $orgValue;
+                            $changeSet[$propName] = $orgValue; // Signal changeset, to-many assocs will be ignored.
                         }
                     }
                 } else if ($isChangeTrackingNotify) {
diff --git a/tests/Doctrine/Tests/ORM/Functional/ManyToManyBasicAssociationTest.php b/tests/Doctrine/Tests/ORM/Functional/ManyToManyBasicAssociationTest.php
index c2df6c467..4ac1a8d00 100644
--- a/tests/Doctrine/Tests/ORM/Functional/ManyToManyBasicAssociationTest.php
+++ b/tests/Doctrine/Tests/ORM/Functional/ManyToManyBasicAssociationTest.php
@@ -3,7 +3,8 @@
 namespace Doctrine\Tests\ORM\Functional;
 
 use Doctrine\Tests\Models\CMS\CmsUser,
-    Doctrine\Tests\Models\CMS\CmsGroup;
+    Doctrine\Tests\Models\CMS\CmsGroup,
+    Doctrine\Common\Collections\ArrayCollection;
 
 require_once __DIR__ . '/../../TestInit.php';
 
@@ -308,4 +309,37 @@ class ManyToManyBasicAssociationTest extends \Doctrine\Tests\OrmFunctionalTestCa
         $this->_em->createQuery("DELETE Doctrine\Tests\Models\CMS\CmsUser u WHERE SIZE(u.groups) = 10")->execute();
         $this->_em->createQuery("UPDATE Doctrine\Tests\Models\CMS\CmsUser u SET u.status = 'inactive' WHERE SIZE(u.groups) = 10")->execute();
     }
+
+    /**
+     * @group DDC-978
+     */
+    public function testClearAndResetCollection()
+    {
+        $user = $this->addCmsUserGblancoWithGroups(2);
+        $group1 = new CmsGroup;
+        $group1->name = 'Developers_New1';
+        $group2 = new CmsGroup;
+        $group2->name = 'Developers_New2';
+
+        $this->_em->persist($group1);
+        $this->_em->persist($group2);
+        $this->_em->flush();
+        $this->_em->clear();
+
+        $user = $this->_em->find(get_class($user), $user->id);
+
+        $coll = new ArrayCollection(array($group1, $group2));
+        $user->groups = $coll;
+        $this->_em->flush();
+        $this->assertInstanceOf('Doctrine\ORM\PersistentCollection', $user->groups,
+            "UnitOfWork should have replaced ArrayCollection with PersistentCollection.");
+        $this->_em->flush();
+
+        $this->_em->clear();
+
+        $user = $this->_em->find(get_class($user), $user->id);
+        $this->assertEquals(2, count($user->groups));
+        $this->assertEquals('Developers_New1', $user->groups[0]->name);
+        $this->assertEquals('Developers_New2', $user->groups[1]->name);
+    }
 }