diff --git a/tools/lint-js.js b/tools/lint-js.js
index 30ff2d313c46c4..4ddbe228d16d37 100644
--- a/tools/lint-js.js
+++ b/tools/lint-js.js
@@ -1,7 +1,7 @@
 'use strict';
 
 const rulesDirs = ['tools/eslint-rules'];
-const extensions = ['.js', '.md'];
+const extensions = ['.js', '.mjs', '.md'];
 // This is the maximum number of files to be linted per worker at any given time
 const maxWorkload = 60;