diff --git a/typo3/sysext/core/Classes/Cache/Backend/ApcBackend.php b/typo3/sysext/core/Classes/Cache/Backend/ApcBackend.php
index bb04fdd..38ddc90 100644
--- a/typo3/sysext/core/Classes/Cache/Backend/ApcBackend.php
+++ b/typo3/sysext/core/Classes/Cache/Backend/ApcBackend.php
@@ -274,7 +274,8 @@ class ApcBackend extends \TYPO3\CMS\Core\Cache\Backend\AbstractBackend implement
 			// Update identifier-to-tag index
 			$existingTags = $this->findTagsByIdentifier($entryIdentifier);
 			if (array_search($entryIdentifier, $existingTags) === FALSE) {
-				apc_store($this->getIdentifierPrefix() . 'ident_' . $entryIdentifier, array_merge($existingTags, $tags));
+                $existingTags[] = $tag;
+				apc_store($this->getIdentifierPrefix() . 'ident_' . $entryIdentifier, $existingTags);
 			}
 		}
 	}