diff --git a/app/models/auth/Group.model.js b/app/models/auth/Group.model.js
index 69ef314..f3648bf 100644
--- a/app/models/auth/Group.model.js
+++ b/app/models/auth/Group.model.js
@@ -42,7 +42,7 @@ class GroupModel extends Model {
 
         if ( this.posix_group_id ) {
             data.objectClass.push('posixGroup')
-            data.gidNumber = this.posix_group_id
+            data.gidNumber = String(this.posix_group_id)
         }
 
         return data