diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 714e518..eb3dd6f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -21,7 +21,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: "3.10"
+        python-version: [3.9]
         # os: [ubuntu-latest, macOS-latest, windows-latest]
         os: [ubuntu-latest]