diff --git a/management/univention-management-console-frontend/umc/tools.js b/management/univention-management-console-frontend/umc/tools.js
index eaf5d2d..ff61a16 100644
--- a/management/univention-management-console-frontend/umc/tools.js
+++ b/management/univention-management-console-frontend/umc/tools.js
@@ -1067,6 +1067,12 @@ define([
 
 					// make sure the attribute is specified in both objects
 					if (!(o.attr in _a) || !(o.attr in _b)) {
+						if (o.attr in _a) {
+							return -1;
+						}
+						if (o.attr in _b) {
+							return 1;
+						}
 						return 0;
 					}