diff --git a/typo3/sysext/extbase/Classes/Persistence/ObjectStorage.php b/typo3/sysext/extbase/Classes/Persistence/ObjectStorage.php
index 7c3fc38..28a219b 100644
--- a/typo3/sysext/extbase/Classes/Persistence/ObjectStorage.php
+++ b/typo3/sysext/extbase/Classes/Persistence/ObjectStorage.php
@@ -157,7 +157,7 @@ class ObjectStorage implements \Countable, \Iterator, \ArrayAccess, ObjectMonito
 	 * @return bool
 	 */
 	public function offsetExists($object) {
-		return isset($this->storage[spl_object_hash($object)]);
+		return is_object($object) && isset($this->storage[spl_object_hash($object)]);
 	}
 
 	/**
diff --git a/typo3/sysext/extbase/Tests/Unit/Persistence/ObjectStorageTest.php b/typo3/sysext/extbase/Tests/Unit/Persistence/ObjectStorageTest.php
index 90390c4..8019ba6 100644
--- a/typo3/sysext/extbase/Tests/Unit/Persistence/ObjectStorageTest.php
+++ b/typo3/sysext/extbase/Tests/Unit/Persistence/ObjectStorageTest.php
@@ -105,6 +105,22 @@ class ObjectStorageTest extends \TYPO3\CMS\Core\Tests\UnitTestCase {
 	/**
 	 * @test
 	 */
+	public function offsetExistsWorksWithEmptyStorageAndIntegerKey() {
+		$objectStorage = new \TYPO3\CMS\Extbase\Persistence\ObjectStorage();
+		$this->assertEquals($objectStorage->offsetExists(0), FALSE);
+	}
+
+	/**
+	 * @test
+	 */
+	public function offsetExistsWorksWithEmptyStorageAndStringKey() {
+		$objectStorage = new \TYPO3\CMS\Extbase\Persistence\ObjectStorage();
+		$this->assertEquals($objectStorage->offsetExists('0'), FALSE);
+	}
+
+	/**
+	 * @test
+	 */
 	public function getInfoReturnsTheDataAssociatedWithTheCurrentIteratorEntry() {
 		$objectStorage = new \TYPO3\CMS\Extbase\Persistence\ObjectStorage();
 		$object1 = new \StdClass();