diff --git a/.github/workflows/ms5.yaml b/.github/workflows/ms5.yaml
index 326c0ec..bddaab9 100644
--- a/.github/workflows/ms5.yaml
+++ b/.github/workflows/ms5.yaml
@@ -9,7 +9,7 @@ jobs:
     runs-on: self-hosted  # or ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.10"]
+        python-version: ["3.9"]
 
     steps:
       #Checkout code