diff --git a/lib/private/group.php b/lib/private/group.php
index 85632248d24bee2b85d9eb9c8ffed1d9e45a27ff..c6846e27581e96a6c23ae7d427f2d4f5d71b87d8 100644
--- a/lib/private/group.php
+++ b/lib/private/group.php
@@ -277,7 +277,8 @@ class OC_Group {
 				$displayNames
 			);
 			if ($diff) {
-				$displayNames = array_merge($diff, $displayNames);
+				// A fix for LDAP users. array_merge loses keys...
+				$displayNames = $diff + $displayNames;
 			}
 		}
 		return $displayNames;