diff --git a/config/permission_groups.lua b/config/permission_groups.lua
index d171bdcc..29b9ff5f 100644
--- a/config/permission_groups.lua
+++ b/config/permission_groups.lua
@@ -101,11 +101,12 @@ Permission_Groups.new_group('Restricted')
 local trusted_time = 60*60*60*10 -- 10 hour
 local standard_time = 60*60*60*3 -- 3 hour
 local function assign_group(player)
+    local current_group_name = player.permission_group and player.permission_group.name or 'None'
     if player.admin then
         Permission_Groups.set_player_group(player,'Admin')
-    elseif player.online_time > trusted_time then
+    elseif player.online_time > trusted_time and current_group_name == 'Trusted' then
         Permission_Groups.set_player_group(player,'Trusted')
-    elseif player.online_time > standard_time then
+    elseif player.online_time > standard_time and current_group_name == 'Guest' then
         Permission_Groups.set_player_group(player,'Standard')
     else
         Permission_Groups.set_player_group(player,'Guest')