diff --git a/.github/workflows/pytest.yaml b/.github/workflows/pytest.yaml
index 3a3d2f5..25993cd 100644
--- a/.github/workflows/pytest.yaml
+++ b/.github/workflows/pytest.yaml
@@ -11,9 +11,9 @@ jobs:
   test:
     strategy:
       matrix:
-        python-version: [3.6, 3.7, 3.8, 3.9, 3.10, 3.11]
+        python-version: [3.6, 3.7, 3.8, 3.9]
     
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     
     steps:
     - name: Checkout code