diff --git a/searx/static/themes/simple/package.json b/searx/static/themes/simple/package.json
index 5150e8153..e84489947 100644
--- a/searx/static/themes/simple/package.json
+++ b/searx/static/themes/simple/package.json
@@ -4,7 +4,7 @@
     "grunt-contrib-concat": "~1.0.1",
     "grunt-contrib-cssmin": "^2.2.1",
     "grunt-contrib-jshint": "~1.1.0",
-    "grunt-contrib-less": "^1.4.1",
+    "grunt-contrib-less": "~3.0.0",
     "grunt-contrib-uglify": "~3.4.0",
     "grunt-contrib-watch": "~1.1.0",
     "grunt-webfont": "^1.7.1",