--- bin/tmake.orig	2004-01-28 13:20:11.000000000 +0800
+++ bin/tmake	2011-10-31 17:51:51.493913956 +0800
@@ -616,7 +616,7 @@
 	s/\#.*//;				# strip comment
 	s/^\s+//;				# strip white space
 	s/\s+$//;
-	if ( /^\s*((?:(?:(?:[\w\-]+\s*:\s*){1,10})?)\w+\s*(\+|\-|\*|\/)?=)/ ) {
+	if ( /^\s*((?:(?:(?:[\w\+\-]+\s*:\s*){1,10})?)\w+\s*(\+|\-|\*|\/)?=)/ ) {
 	    $var = $1;				# var also contains the ".="
 	    s/^.*?=\s*//;
 	    if ( /^\<\<(.*)$/ ) {