diff --git a/src/accessories/CleanUpHelper.ttslua b/src/accessories/CleanUpHelper.ttslua
index 9be7d435..ff09033b 100644
--- a/src/accessories/CleanUpHelper.ttslua
+++ b/src/accessories/CleanUpHelper.ttslua
@@ -422,7 +422,7 @@ end
 -- get value with respect to override value
 function getOptionValue()
   -- don't clean up playermats if playing a prelude from the list
-  if preludeList[scenarioName] then
+  if scenarioName and preludeList[scenarioName] then
     return false
   else
     return options["tidyPlayermats"]