diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 56a836ffb..bddcbab74 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -113,6 +113,9 @@ jobs:
         continue-on-error: true
       - name: Install python dependencies
         run: python -m pip install codecov tox
+      - name: Pin tox on Windows
+        if: startsWith(runner.os, 'windows')
+        run: python -m pip install codecov tox==3.8.3
       - name: Run python tests
         run: tox -e py
       - name: Publish coverage