diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index 7373c68..61d137b 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -13,8 +13,12 @@ jobs:
 
     strategy:
       matrix:
-        os: [ ubuntu-latest ]
-        ruby: [ '2.3', '2.7', '3.0', '3.1', '3.2', 'jruby-9.2', 'jruby-9.4', 'truffleruby-22.3' ]
+        os: [
+          ubuntu-latest ]
+        ruby: [
+          '2.7', '3.0', '3.1', '3.2', '3.3',
+          'jruby-9.2', 'jruby-9.4',
+          'truffleruby-22.3' ]
         experimental: [ false ]
       fail-fast: false
     runs-on: ${{matrix.os}}