diff --git a/lib/user.php b/lib/user.php
index b19af940795b64087852be8ea7bda0f2f494f390..226b716188d3c71cfbc8b2bdd28198df164e9347 100644
--- a/lib/user.php
+++ b/lib/user.php
@@ -527,7 +527,7 @@ class OC_User {
 		foreach (self::$_usedBackends as $backend) {
 			$backendDisplayNames = $backend->getDisplayNames($search, $limit, $offset);
 			if (is_array($backendDisplayNames)) {
-				$displayNames = array_merge($displayNames, $backendDisplayNames);
+				$displayNames = $displayNames + $backendDisplayNames;
 			}
 		}
 		asort($displayNames);