diff --git a/lib/Properties.hs b/lib/Properties.hs
index 46afcb97757a084f243e332f3b96000bf0d268fb..c4fc45867677cf603784d0a377c024694245b6e5 100644
--- a/lib/Properties.hs
+++ b/lib/Properties.hs
@@ -143,7 +143,9 @@ checkMapProperty p@(Property name _) = case name of
   _ | T.toLower name == "script" ->
       unwrapString p $ \str ->
         unless (("https://static.rc3.world/scripts" `isPrefixOf` str) &&
-                (not $ "/../" `isInfixOf` str))
+                (not $ "/../" `isInfixOf` str) &&
+                (not $ "%" `isInfixOf` str) &&
+                (not $ "@" `isInfixOf` str))
         $ forbid "only scripts hosted on static.rc3.world are allowed."
     | name `elem` ["jitsiRoom", "bbbRoom", "playAudio", "openWebsite"
                   , "url", "exitUrl", "silent", "getBadge"]