diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 840c516..3d661b6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,7 +9,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ['2.7', '3.0', '3.1', '3.2']
+        ruby: ['2.5', '2.6', '2.7', '3.0', '3.1', '3.2']
     steps:
       - name: Check out repository code
         uses: actions/checkout@v3