diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
index addf9244..e0c77b81 100644
--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -7,6 +7,9 @@ jobs:
     runs-on: macos-latest
     steps:
     - uses: actions/checkout@v5
+    - uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: 3.4
     - name: Install dependencies
       run: |
         gem install bundler --no-document
diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index 08090a99..defaa598 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -6,7 +6,7 @@ jobs:
   test:
     strategy:
       matrix:
-        ruby: [ head, 3.3, 3.2, 3.1, 3.0 ]
+        ruby: [ head, 3.4, 3.3, 3.2 ]
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v5
diff --git a/.github/workflows/windows.yml b/.github/workflows/windows.yml
index 962e1e1a..1b27c48a 100644
--- a/.github/workflows/windows.yml
+++ b/.github/workflows/windows.yml
@@ -7,7 +7,7 @@ jobs:
     runs-on: windows-latest
     strategy:
       matrix:
-        ruby: [ 'mingw', 'mswin', '3.3' ]
+        ruby: [ 'mingw', 'mswin', '3.4' ]
     steps:
     - uses: actions/checkout@v5
       with: