--- a/src/tools/genglsl.c	Thu Dec 23 18:14:29 2010 +1000
+++ b/src/tools/genglsl.c	Thu Apr 07 21:42:55 2011 +1000
@@ -254,7 +254,7 @@
     if( oldext == NULL ) {
         return g_strdup_printf("%s%s", basename, ext);
     } else {
-        return g_strdup_printf("%.*s%s", oldext-basename, basename, ext);
+        return g_strdup_printf("%.*s%s", (int)(oldext-basename), basename, ext);
     }
 }