diff --git a/packages/google-cloud-oslogin/.eslintrc.yml b/packages/google-cloud-oslogin/.eslintrc.yml
index bed57fbc42c..65f1dce6c0c 100644
--- a/packages/google-cloud-oslogin/.eslintrc.yml
+++ b/packages/google-cloud-oslogin/.eslintrc.yml
@@ -11,3 +11,4 @@ rules:
   block-scoped-var: error
   eqeqeq: error
   no-warning-comments: warn
+  no-var: error