diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index f63d673a..7b781557 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -30,7 +30,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby: [2.6, 2.7, 3.0]
+        ruby: ['2.6', '2.7', '3.0', '3.1']
     steps:
       - name: Check out repository code
         uses: actions/checkout@v2