diff --git a/index.js b/index.js
index f2b9d6e..d20f540 100644
--- a/index.js
+++ b/index.js
@@ -22,7 +22,8 @@ module.exports = {
     'new-line-between-declarations': require('./lib/rules/new-line-between-declarations'),
     'new-line-before-expect': require('./lib/rules/new-line-before-expect'),
     'prefer-jasmine-matcher': require('./lib/rules/prefer-jasmine-matcher'),
-    'prefer-toHaveBeenCalledWith': require('./lib/rules/prefer-toHaveBeenCalledWith')
+    'prefer-toHaveBeenCalledWith': require('./lib/rules/prefer-toHaveBeenCalledWith'),
+    'prefer-toBeUndefined': require('./lib/rules/prefer-toBeUndefined')
   },
   configs: {
     recommended: {