diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 882ece3..5022cc4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -15,7 +15,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [ 2.4, 2.5, 2.6, 2.7, "3.0", 3.1, 3.2, 3.3]
+        ruby: [ 2.4, 2.5, 2.6, 2.7, "3.0", 3.1, 3.2, 3.3, 3.4 ]
     name: ${{ matrix.ruby }}
     env:
       BUNDLE_GEMFILE: .ci.gemfile