diff --git a/.github/workflows/pytest.yml b/.github/workflows/pytest.yml
index 8f60a7b7f7..89144f4053 100644
--- a/.github/workflows/pytest.yml
+++ b/.github/workflows/pytest.yml
@@ -8,6 +8,7 @@ on:
     - 'gym-unity/**'
     - 'test_constraints*.txt'
     - 'test_requirements.txt'
+    - '.github/workflows/pytest.yml'
   push:
     branches: [master]
 
@@ -44,7 +45,8 @@ jobs:
       run: python -c "import sys; print(sys.version)"
     - name: Install dependencies
       run: |
-        python -m pip install --upgrade pip
+        # pin pip to workaround https://github.com/pypa/pip/issues/9180
+        python -m pip install pip==20.2
         python -m pip install --upgrade setuptools
         python -m pip install --progress-bar=off -e ./ml-agents-envs -c ${{ matrix.pip_constraints }}
         python -m pip install --progress-bar=off -e ./ml-agents -c ${{ matrix.pip_constraints }}