diff --git a/Makefile b/Makefile
index 36fcca4..44dca89 100644
--- a/Makefile
+++ b/Makefile
@@ -8,6 +8,7 @@ incremental: htmls sasss
 	cp sass/*.css out
 	cd out; unzip -n font-awesome-4.7.0.zip
 	. virtual_env/bin/activate; python -m trivial_static_image_gallery config.ini
+	-yes n | gzip -rk9q out 2>/dev/null
 
 htmls: virtual_env
 	rm -f tpl/*.html