diff --git a/PBot/Factoids.pm b/PBot/Factoids.pm
index 2b700abe..3cf14a98 100644
--- a/PBot/Factoids.pm
+++ b/PBot/Factoids.pm
@@ -411,7 +411,7 @@ sub expand_factoid_vars {
       last if ++$depth >= 100;
       my ($a, $v) = ($1, $2);
       $v =~ s/(.):$/$1/;
-      next if $v =~ m/^_/; # underscore-prefixed vars reserved for code-factoids
+      next if $v =~ m/^[\W]/; # special character prefix skipped for shell/code-factoids/etc
       next if $v =~ m/^(nick|channel|randomnick|arglen|args|arg\[.+\]|[_0])$/i; # don't override special variables
       next if @exclude && grep { $v =~ m/^\Q$_\E$/i } @exclude;