diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index b94cfa4..c067936 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -8,7 +8,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [3.7, 3.8, 3.9, 3.10]
+        python-version: ['3.7', '3.8', '3.9', '3.10']
     steps:
     - uses: actions/checkout@v2
     - name: Set up Python ${{ matrix.python-version }}