diff --git a/mge/events.nut b/mge/events.nut
index d35890f..b3aaaa6 100644
--- a/mge/events.nut
+++ b/mge/events.nut
@@ -322,7 +322,7 @@ class MGE_Events
 
 				local _arena = Arenas[arena_name]
 				if (arena.State == AS_IDLE && arena.CurrentPlayers.len() == arena.MaxPlayers)
-					if (!arena.IsUltiduo && !(arena.IsBBall && arena.State == AS_IDLE))
+					if (!arena.IsUltiduo && !(arena.IsBBall && arena.State == AS_IDLE && arena.IsCustomRuleset))
 						EntFireByHandle(player, "RunScriptCode", "SetArenaState(self.GetScriptScope().arena_info.name, AS_COUNTDOWN)", COUNTDOWN_START_DELAY, null, null)
 					else if (arena.IsUltiduo)
 					{
diff --git a/mge/functions.nut b/mge/functions.nut
index a0bbe31..0352529 100644
--- a/mge/functions.nut
+++ b/mge/functions.nut
@@ -1368,7 +1368,7 @@
 				EntFireByHandle(arena.BBall.ground_ball, "Kill", "", -1, null, null)
 			}
 
-			if (arena.IsCustomRuleset)
+			if ("IsCustomRuleset" in arena && arena.IsCustomRuleset)
 			{
 				foreach(p, _ in arena.CurrentPlayers)
 				{