diff --git a/tcshrc.prompt.defs b/tcshrc.prompt.defs
index c1dba38..37b164b 100644
--- a/tcshrc.prompt.defs
+++ b/tcshrc.prompt.defs
@@ -145,8 +145,8 @@ set referencechars_raw="${referencechars_raw} 2620"
 
 _debug "Building unicode sigils table...."
 if( ! $?CSHENV_NO_UNICODE_PRINTF ) then
-	_debug "${referencechars_raw:as/ /_\U0000/:as/_/ /:as/ 00001/ 0001/}"
-	set referencechars_original=( `printf "${referencechars_raw:as/ /_\U0000/:as/_/ /:as/ 00001/ 0001/}"` )
+	_debug "${referencechars_raw:as/ /_0000/:as/_00001/_0001/:as/_/ \U/:q}"
+	set referencechars_original=( `printf "${referencechars_raw:as/ /_0000/:as/_00001/_0001/:as/_/ \U/:q}"`)
 else
 	# Safe fallback for when there's no unicode printf
 	set referencechars_original="A B C D X Y Z"