diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ae5b13cf..e306eb50 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -7,7 +7,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-20.04, windows-2019]
-        python-version: [3.10, 3.9, 3.8, 3.7, 3.6]
+        python-version: ["3.10", "3.9", "3.8", "3.7", "3.6"]
         environment: ['3.8', '3.10', '3.9', '3.7', '3.6', 'interpreter']
     steps:
       - name: Checkout code