diff --git a/apps/user_ldap/group_ldap.php b/apps/user_ldap/group_ldap.php
index 63476525dfa..f87fe1b5cab 100644
--- a/apps/user_ldap/group_ldap.php
+++ b/apps/user_ldap/group_ldap.php
@@ -531,7 +531,7 @@ class GROUP_LDAP extends BackendUtility implements \OCP\GroupInterface {
 		}
 
 		if(isset($this->cachedGroupsByMember[$uid])) {
-			$groups[] = $this->cachedGroupsByMember[$uid];
+			$groups = array_merge($groups, $this->cachedGroupsByMember[$uid]);
 		} else {
 			$groupsByMember = array_values($this->getGroupsByMember($uid));
 			$groupsByMember = $this->access->ownCloudGroupNames($groupsByMember);