diff --git a/.github/workflows/testrunner.yml b/.github/workflows/testrunner.yml
index 65be01b..281ab20 100644
--- a/.github/workflows/testrunner.yml
+++ b/.github/workflows/testrunner.yml
@@ -10,7 +10,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        python-version: [3.8, 3.10, 3.12, pypy-3.10]
+        python-version: ["3.8", "3.10", "3.12", "pypy-3.10"]
     steps:
     - uses: actions/checkout@v4
     - name: Set up Python ${{ matrix.python-version }}