diff --git a/.github/workflows/repostat_ubuntu.yml b/.github/workflows/repostat_ubuntu.yml
index e8c952a..8cc6cd4 100644
--- a/.github/workflows/repostat_ubuntu.yml
+++ b/.github/workflows/repostat_ubuntu.yml
@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        python-version: [3.7, 3.8, 3.9, 3.10, 3.11]
+        python-version: ['3.7', '3.8', '3.9', '3.10', '3.11']
 
     steps:
     - uses: actions/checkout@v2