diff --git a/manage b/manage
index 024fdf39..c042d8eb 100755
--- a/manage
+++ b/manage
@@ -310,14 +310,11 @@ node.env() {
 }
 
 node.clean() {
-
     build_msg CLEAN "locally installed npm dependencies"
-    rm -rf \
-       ./searx/static/themes/oscar/package-lock.json \
-       ./searx/static/themes/oscar/node_modules \
-       ./searx/static/themes/simple/package-lock.json \
-       ./searx/static/themes/simple/node_modules
-       ./searx/static/themes/simple/ion.less \
+    (   set -e
+        npm --prefix searx/static/themes/oscar run clean
+        npm --prefix searx/static/themes/simple run clean
+    )
     dump_return $?
 }
 
diff --git a/searx/static/themes/oscar/package.json b/searx/static/themes/oscar/package.json
index 8a3d4878..94883873 100644
--- a/searx/static/themes/oscar/package.json
+++ b/searx/static/themes/oscar/package.json
@@ -1,23 +1,27 @@
 {
     "devDependencies": {
-        "grunt": "^1.3.0",
-        "grunt-cli": "^1.3.2",
+        "grunt": "~1.4.1",
+        "grunt-cli": "^1.4.3",
         "grunt-contrib-concat": "~1.0.1",
         "grunt-contrib-copy": "^1.0.0",
         "grunt-contrib-jshint": "~3.0.0",
         "grunt-contrib-less": "~3.0.0",
-        "grunt-contrib-uglify": "~5.0.0",
-        "grunt-contrib-watch": "~1.1.0"
-    },
-    "scripts": {
-        "build": "npm install && grunt",
-        "start": "grunt watch",
-        "test": "grunt"
+        "grunt-contrib-uglify": "~5.0.1",
+        "grunt-contrib-watch": "~1.1.0",
+        "jslint": "^0.12.1",
+        "less": "^4.1.1",
+        "less-plugin-clean-css": "^1.5.1"
     },
     "dependencies": {
         "bootstrap": "^3.4.1",
         "corejs-typeahead": "^1.3.1",
         "jquery": "^3.6.0",
         "leaflet": "^1.7.1"
+    },
+    "scripts": {
+        "all": "npm install && grunt",
+        "build": "grunt",
+        "watch": "grunt watch",
+        "clean": "rm -Rf node_modules package-lock.json"
     }
 }
diff --git a/searx/static/themes/simple/package.json b/searx/static/themes/simple/package.json
index e23157bf..22357a4c 100644
--- a/searx/static/themes/simple/package.json
+++ b/searx/static/themes/simple/package.json
@@ -22,6 +22,7 @@
   "scripts": {
     "all": "npm install && grunt",
     "build": "grunt",
-    "watch": "grunt watch"
+    "watch": "grunt watch",
+    "clean": "rm -Rf node_modules package-lock.json ion.less"
   }
 }