diff --git a/skel/make.sh b/skel/make.sh
index 3293c4e..ee93f2f 100755
--- a/skel/make.sh
+++ b/skel/make.sh
@@ -42,7 +42,7 @@ source scripts/functions.sh || exit 1
 
 
 # List of directories which will be emptied by clean.
-OUTPUT_DIRS="obj"
+OUTPUT_DIRS="obj html"