diff --git a/tools/update_html b/tools/update_html
index 78a790aa..8110b010 100755
--- a/tools/update_html
+++ b/tools/update_html
@@ -49,6 +49,7 @@ done
 
 for f in apps/*.mu
 do
+  test $# -gt 0  &&  test $1 != $f  &&  continue
   ( cd $(dirname $f)
     ctags -x ../[0-9]*.subx ../[0-9]*.mu $(basename $f) > /tmp/tags
   )