diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 89db26b..c76d08e 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -12,7 +12,7 @@ on:
 
 jobs:
   test:
-    uses: ocadotechnology/codeforlife-workspace/.github/workflows/test-python-code.yaml@main
+    uses: ocadotechnology/codeforlife-workspace/.github/workflows/test-python-code.yaml@polish_mypy
     with:
       # Cannot be set with an env var. Value must match in the release job.
       python-version: 3.8