diff --git a/tensorflow_hub/.github/workflows/contributions-validator.yml b/tensorflow_hub/.github/workflows/contributions-validator.yml
new file mode 100644
index 000000000..acc2dbbf8
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+++ b/tensorflow_hub/.github/workflows/contributions-validator.yml
@@ -0,0 +1,42 @@
+# Copyright 2020 The TensorFlow Hub Authors. All Rights Reserved.
+#
+# 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: External contributions validator
+
+on:
+  pull_request:
+
+jobs:
+  test-changed-md-files:
+    runs-on: ubuntu-16.04
+    name: Test changed markdown documentation files.
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions/setup-python@v1
+        with:
+          python-version: '3.6'
+      - name: Install packages
+        run: |
+          pip install absl-py tensorflow tensorflow_hub
+          pip freeze all
+      - name: Debug information
+        run: |
+          echo $(git status)
+          echo $(git branch)
+          echo $(git remote)
+          echo $(git diff origin/master --name-only)
+          echo $(ls)
+      - name: Run validator on changed files
+        run: |
+          git diff origin/master --name-only --relative=tfhub_dev/assets | xargs python3.6 ./tfhub_dev/tools/validator.py