diff --git a/src/controllers/group.js b/src/controllers/group.js
index 9b604ca..c0d2b45 100644
--- a/src/controllers/group.js
+++ b/src/controllers/group.js
@@ -71,6 +71,8 @@ class GroupController {
 
         let result = await GroupService.getAdminId(groupId);
 
+        if (!result) result = -1
+
         return res.status(200).send(result.toString())
     }
 }