diff --git a/.github/workflows/go.yml b/.github/workflows/go.yml
index 5ff2d04..45438e7 100644
--- a/.github/workflows/go.yml
+++ b/.github/workflows/go.yml
@@ -30,6 +30,9 @@ jobs:
     - name: Check
       run: make check
 
+    - name: Fail if files changed
+      run: git diff --exit-code
+
     - name: Test
       env:
         LOGIN_NETID: ${{ secrets.LOGIN_NETID }}