diff --git a/locales/en.json b/locales/en.json
index 6f9d28a40..d3bdeed04 100644
--- a/locales/en.json
+++ b/locales/en.json
@@ -218,7 +218,7 @@
     "group_creation_failed": "Group creation failed for group '{group}'",
     "group_deleted": "Group '{group}' deleted",
     "group_deletion_failed": "Group '{group} 'deletion failed",
-    "group_deletion_not_allowed": "You are not allowed to remove the main group of the user {user:s}",
+    "group_deletion_not_allowed": "The group {group:s} cannot be deleted manually.",
     "group_info_failed": "Group info failed",
     "group_unknown": "Group {group:s} unknown",
     "group_updated": "Group '{group}' updated",
diff --git a/src/yunohost/user.py b/src/yunohost/user.py
index 3e818f7ea..d6981ed36 100644
--- a/src/yunohost/user.py
+++ b/src/yunohost/user.py
@@ -594,11 +594,9 @@ def user_group_delete(operation_logger, auth, groupname, force=False, sync_perm=
     """
     from yunohost.permission import permission_sync_to_user
 
-    if not force \
-       and (groupname == 'all_users' or
-            groupname == 'admins' or
-            groupname in user_list(auth, fields=['uid'])['users']):
-        raise YunohostError('group_deletion_not_allowed', user=groupname)
+    forbidden_groups = ["all_users", "admins"] + user_list(auth, fields=['uid'])['users'].keys()
+    if not force and groupname in forbidden_groups:
+        raise YunohostError('group_deletion_not_allowed', group=groupname)
 
     operation_logger.start()
     if not auth.remove('cn=%s,ou=groups' % groupname):
@@ -640,7 +638,7 @@ def user_group_update(operation_logger, auth, groupname, add_user=None, remove_u
     else:
         group['member'] = []
 
-    existing_users = user_list(auth, fields=['uid'])['users']
+    existing_users = user_list(auth, fields=['uid'])['users'].keys()
 
     if add_user:
         if not isinstance(add_user, list):