diff --git a/.eslintrc.json b/.eslintrc.json
index b1e5b0a5183..68f1af34449 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -11,6 +11,7 @@
     "parser": "typescript-eslint-parser",
     "plugins": [
         "import",
+        "markdown",
         "typescript"
     ],
     "rules": {
diff --git a/docs/develeloper-guide/rules/how-to-test-rules.md b/docs/develeloper-guide/rules/how-to-test-rules.md
index 743d3624609..8d14e3d29b6 100644
--- a/docs/develeloper-guide/rules/how-to-test-rules.md
+++ b/docs/develeloper-guide/rules/how-to-test-rules.md
@@ -34,24 +34,28 @@ need to:
 * `string` containing the response for `/` (HTML, plain text, etc.).
 * `object` with paths as properties names and their content as values:
 
+  <!-- eslint-disable no-unused-vars -->
+
   ```js
-  {
-    '/': 'some HTML here',
-    'site.webmanifest': '{ "property1": "value1" }'
-  }
+    const tests = [{
+        '/': 'some HTML here',
+        'site.webmanifest': { property: 'value' }
+    }];
   ```
 
 * You can even specify the status code for the response for
   a specific path:
 
+  <!-- eslint-disable no-unused-vars -->
+
   ```js
-  {
-      '/': 'some HTML here',
-      '/site.webmanifest': {
-          statusCode: 200,
-          content: 'The content of the response'
-      }
-  }
+    const tests = [{
+        '/': 'some HTML here',
+        '/site.webmanifest': {
+            content: 'The content of the response',
+            statusCode: 200
+        }
+    }];
   ```
 
 In the last example, if you don't specify `content`, the response
diff --git a/package.json b/package.json
index 62a2313f447..1d7b2c93494 100644
--- a/package.json
+++ b/package.json
@@ -9,7 +9,7 @@
     "build:ts": "tsc --outDir dist --rootDir src",
     "build": "npm-run-all build:*",
     "clean": "rimraf dist",
-    "lint": "eslint \"src/**/*.ts\"",
+    "lint": "eslint --ext ts src/ --ext md . --ignore-pattern dist/*",
     "site": "node dist/bin/sonar --debug",
     "test": "npm run lint && npm run clean && npm run build && nyc ava",
     "watch": "npm run build && npm-run-all --parallel -c watch:*",
@@ -65,6 +65,7 @@
     "cpx": "^1.5.0",
     "eslint-config-airbnb-base": "^11.1.0",
     "eslint-plugin-import": "^2.2.0",
+    "eslint-plugin-markdown": "^1.0.0-beta.4",
     "eslint-plugin-typescript": "^0.1.0",
     "express": "^4.15.2",
     "leche": "^2.1.2",
diff --git a/src/lib/rules/disallowed-headers/disallowed-headers.md b/src/lib/rules/disallowed-headers/disallowed-headers.md
index 3774ee4361a..170f1c3bad5 100644
--- a/src/lib/rules/disallowed-headers/disallowed-headers.md
+++ b/src/lib/rules/disallowed-headers/disallowed-headers.md
@@ -66,9 +66,9 @@ Yes, you can use:
 E.g. The following configuration will make the rule allow responses
 to be served with the `Server` HTTP headers, but not with `Custom-Header`.
 
-```js
+```json
 "disallowed-headers": [ "warning", {
-    ignore: ['Server'],
-    include: ['Custom-Header']
+    "ignore": ["Server"],
+    "include": ["Custom-Header"]
 }]
 ```