diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index dbc0f7b..64110f1 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -1,3 +1,17 @@
+# Copyright 2020 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 name: "Continuous Integration"
 on:
   push:
@@ -21,7 +35,9 @@ jobs:
         git add --all
         git -c user.name="CI Bot" -c user.email="<>" commit -m "initial state"
         addlicense ./
-        test -z "$(git status -s | tee /dev/stderr)"
+        if [[ -n $(git diff) ]]; then
+          exit 1
+        fi
     - name: Setup Cluster
       run: |
         set -x