diff --git a/.gitea/workflows/test.yml b/.gitea/workflows/test.yml
index 5655eeea..cf1dd7c9 100644
--- a/.gitea/workflows/test.yml
+++ b/.gitea/workflows/test.yml
@@ -64,6 +64,13 @@ jobs:
     # leak sanitizer sometimes crashes
     - run: cd /root/vitastor/build && ASAN_OPTIONS=detect_leaks=0 make -j16 test
 
+  npm_lint:
+    runs-on: ubuntu-latest
+    needs: build
+    container: ${{env.TEST_IMAGE}}:${{github.sha}}
+    steps:
+    - run: cd /root/vitastor/mon && npm run lint
+
   test_add_osd:
     runs-on: ubuntu-latest
     needs: build
diff --git a/mon/.eslintrc.js b/mon/.eslintrc.js
new file mode 100644
index 00000000..385082bb
--- /dev/null
+++ b/mon/.eslintrc.js
@@ -0,0 +1,55 @@
+module.exports = {
+    "env": {
+        "es6": true,
+        "node": true
+    },
+    "extends": [
+        "eslint:recommended",
+        "plugin:node/recommended"
+    ],
+    "parserOptions": {
+        "ecmaVersion": 2020
+    },
+    "plugins": [
+    ],
+    "rules": {
+        "indent": [
+            "error",
+            4
+        ],
+        "brace-style": [
+            "error",
+            "allman",
+            { "allowSingleLine": true }
+        ],
+        "linebreak-style": [
+            "error",
+            "unix"
+        ],
+        "semi": [
+            "error",
+            "always"
+        ],
+        "require-atomic-updates": [
+            "off"
+        ],
+        "no-useless-escape": [
+            "off"
+        ],
+        "no-control-regex": [
+            "off"
+        ],
+        "no-unused-vars": [
+            "off"
+        ],
+        "no-empty": [
+            "off"
+        ],
+        "no-process-exit": [
+            "off"
+        ],
+        "node/shebang": [
+            "off"
+        ]
+    }
+};
diff --git a/mon/dsl_pgs.js b/mon/dsl_pgs.js
index cbf87d6f..f1813df4 100644
--- a/mon/dsl_pgs.js
+++ b/mon/dsl_pgs.js
@@ -152,6 +152,7 @@ function parse_pg_dsl(text)
             else if (rule[2] === '(')
             {
                 rule[2] = [];
+                // eslint-disable-next-line no-constant-condition
                 while (true)
                 {
                     if (i > tokens.length-1)
diff --git a/mon/mon.js b/mon/mon.js
index c72cd54f..244785f0 100644
--- a/mon/mon.js
+++ b/mon/mon.js
@@ -747,6 +747,7 @@ class Mon
         this.save_last_clean_running = true;
         // last_clean_pgs is used to avoid extra data move when observing a series of changes in the cluster
         const new_clean_pgs = { items: {} };
+        // eslint-disable-next-line indent
     next_pool:
         for (const pool_id in this.state.config.pools)
         {
@@ -829,6 +830,7 @@ class Mon
     async become_master()
     {
         const state = { ...this.get_mon_state(), id: ''+this.etcd_lease_id };
+        // eslint-disable-next-line no-constant-condition
         while (1)
         {
             const res = await this.etcd_call('/kv/txn', {
@@ -1316,7 +1318,7 @@ class Mon
             for (const k in rules)
             {
                 if (!levels[k] || typeof rules[k] !== 'string' &&
-                    (!rules[k] instanceof Array ||
+                    (!(rules[k] instanceof Array) ||
                     rules[k].filter(s => typeof s !== 'string' && typeof s !== 'number').length > 0))
                 {
                     if (warn)
diff --git a/mon/package.json b/mon/package.json
index 550d0148..16cd0c96 100644
--- a/mon/package.json
+++ b/mon/package.json
@@ -11,5 +11,15 @@
   "dependencies": {
     "sprintf-js": "^1.1.2",
     "ws": "^7.2.5"
+  },
+  "devDependencies": {
+    "eslint": "^8.0.0",
+    "eslint-plugin-node": "^11.1.0"
+  },
+  "engines": {
+    "node": ">=12.0.0"
+  },
+  "scripts": {
+    "lint": "eslint *.js"
   }
 }
diff --git a/mon/simple-offsets.js b/mon/simple-offsets.js
index e2ae667d..72a5b6de 100644
--- a/mon/simple-offsets.js
+++ b/mon/simple-offsets.js
@@ -38,7 +38,7 @@ async function run()
         const st = await fs.stat(options.device);
         options.device_block_size = st.blksize;
         if (st.isBlockDevice())
-            device_size = Number(await system("/sbin/blockdev --getsize64 "+options.device))
+            device_size = Number(await system("/sbin/blockdev --getsize64 "+options.device));
         else
             device_size = st.size;
     }
diff --git a/mon/test-optimize.js b/mon/test-optimize.js
index 34b357aa..0ae931aa 100644
--- a/mon/test-optimize.js
+++ b/mon/test-optimize.js
@@ -20,7 +20,7 @@ const osd_tree = {
     },
     500: {
         4: 3.58498,
-//        8: 3.58589,
+        /*8: 3.58589,*/
         9: 3.63869,
     },
     600: {
diff --git a/rpm/vitastor-el7.spec b/rpm/vitastor-el7.spec
index d55be76e..e808a8ea 100644
--- a/rpm/vitastor-el7.spec
+++ b/rpm/vitastor-el7.spec
@@ -104,7 +104,7 @@ rm -rf $RPM_BUILD_ROOT
 %make_install
 . /opt/rh/rh-nodejs12/enable
 cd mon
-npm install
+npm install --production
 cd ..
 mkdir -p %buildroot/usr/lib/vitastor
 cp -r mon %buildroot/usr/lib/vitastor
diff --git a/rpm/vitastor-el8.spec b/rpm/vitastor-el8.spec
index 8f74037d..a7323eb2 100644
--- a/rpm/vitastor-el8.spec
+++ b/rpm/vitastor-el8.spec
@@ -101,7 +101,7 @@ Vitastor fio drivers for benchmarking.
 rm -rf $RPM_BUILD_ROOT
 %make_install
 cd mon
-npm install
+npm install --production
 cd ..
 mkdir -p %buildroot/usr/lib/vitastor
 cp -r mon %buildroot/usr/lib/vitastor
diff --git a/rpm/vitastor-el9.spec b/rpm/vitastor-el9.spec
index f6c5f06f..859ce169 100644
--- a/rpm/vitastor-el9.spec
+++ b/rpm/vitastor-el9.spec
@@ -94,7 +94,7 @@ Vitastor fio drivers for benchmarking.
 rm -rf $RPM_BUILD_ROOT
 %cmake_install
 cd mon
-npm install
+npm install --production
 cd ..
 mkdir -p %buildroot/usr/lib/vitastor
 cp -r mon %buildroot/usr/lib/vitastor