diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0bd5221..a3226c2 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -15,10 +15,11 @@ jobs:
     strategy:
       matrix:
         ruby-version:
-          - 2.7
-          - 3.0
-          - 3.1
-          - 3.2
+          - "2.7"
+          - "3.0"
+          - "3.1"
+          - "3.2"
+          - "3.3"
       fail-fast: false
     steps:
       - uses: actions/checkout@v2