diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index e4a91da5b..9f8b8189b 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -37,7 +37,7 @@ jobs:
         python-version:
           - '3.7'
           - '3.8'
-          - '3.9'
+          - '3.9.6' # XXX: Regression in 3.9.7 with gitpython-3.1.20
     steps:
     - uses: actions/checkout@v2
     - uses: actions/setup-python@v2
@@ -53,8 +53,10 @@ jobs:
           && chmod +x /opt/bin/jb
     - name: Update PATH
       run: echo "/opt/bin" >> $GITHUB_PATH
+    - name: Extract Python minor version from matrix python-version
+      run: echo "PYVER=$(echo ${{ matrix.python-version}} |cut -d. -f1,2)" >> $GITHUB_ENV
     - name: Run tests on Python ${{ matrix.python-version }}
-      run: make test_py${{ matrix.python-version }}
+      run: make bench_py${PYVER}
   benchs:
     runs-on: ubuntu-latest
     strategy:
@@ -62,7 +64,7 @@ jobs:
         python-version:
           - '3.7'
           - '3.8'
-          - '3.9'
+          - '3.9.6' # XXX: Regression in 3.9.7 with gitpython-3.1.20
     steps:
     - uses: actions/checkout@v2
     - uses: actions/setup-python@v2
@@ -78,15 +80,17 @@ jobs:
           && chmod +x /opt/bin/jb
     - name: Update PATH
       run: echo "/opt/bin" >> $GITHUB_PATH
+    - name: Extract Python minor version from matrix python-version
+      run: echo "PYVER=$(echo ${{ matrix.python-version}} |cut -d. -f1,2)" >> $GITHUB_ENV
     - name: Run benchmarks on Python ${{ matrix.python-version }}
-      run: make bench_py${{ matrix.python-version }}
+      run: make bench_py${PYVER}
   integration:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
     - uses: actions/setup-python@v2
       with:
-        python-version: '3.9'
+        python-version: '3.9.6' # XXX: Regression in 3.9.7 with gitpython-3.1.20
     - name: Install Poetry, setup Poetry virtualenv, and build Kapitan helm bindings
       run: |
         pip install poetry
diff --git a/Dockerfile b/Dockerfile
index f43148cb4..b8e7df7ce 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM docker.io/python:3.9.7-slim-buster AS base
+FROM docker.io/python:3.9.6-slim-buster AS base
 
 ENV HOME=/app