diff --git a/src/controllers/GroupsController.ts b/src/controllers/GroupsController.ts
index e0e4425..36446f9 100644
--- a/src/controllers/GroupsController.ts
+++ b/src/controllers/GroupsController.ts
@@ -414,9 +414,7 @@ export class GroupsController {
 			h.error(404, "Membership not found!");
 
 		// If the user is an admin, he must not be the last admin of the group
-		// TODO : use new method
-		if(userID == h.getUserId() && currUserMembership.level == GroupMembershipLevels.ADMINISTRATOR
-			&& await GroupsHelper.CountMembersAtLevel(groupID, GroupMembershipLevels.ADMINISTRATOR) == 1)
+		if(userID == h.getUserId() && await GroupsHelper.IsLastAdmin(groupID, userID))
 			h.error(401, "You are the last administrator of this group!");