diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index c54f4cd..6626571 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -19,6 +19,7 @@ jobs:
   tests:
     runs-on: ubuntu-latest
     strategy:
+      max-parallel: 1
       matrix:
         python-version: [3.9, 3.10.x, 3.11, 3.12]
     steps: