diff --git a/tools/eslint-rules/required-modules.js b/tools/eslint-rules/required-modules.js
index 7691d5dd7d91a0..4a444809b7115c 100644
--- a/tools/eslint-rules/required-modules.js
+++ b/tools/eslint-rules/required-modules.js
@@ -75,7 +75,7 @@ module.exports = function(context) {
       if (foundModules.length < requiredModules.length) {
         var missingModules = requiredModules.filter(
           function(module) {
-            return foundModules.indexOf(module === -1);
+            return foundModules.indexOf(module) === -1;
           }
         );
         missingModules.forEach(function(moduleName) {