diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index e811e9f..07b627d 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -22,7 +22,7 @@ jobs:
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1
       with:
-        ruby-version: 3.3
+        ruby-version: 3.4
         bundler-cache: true
     - uses: r7kamura/rubocop-problem-matchers-action@v1
     - run: bundle exec rubocop --parallel
@@ -46,7 +46,7 @@ jobs:
 
     strategy:
       matrix:
-        ruby-version: ['3.1', '3.2', '3.3', '3.4.0-preview2']
+        ruby-version: ['3.1', '3.2', '3.3', '3.4']
         cassandra-version: ['3', '4', '5']
 
     name: Linux, Cassandra ${{ matrix.cassandra-version }}, Ruby ${{ matrix.ruby-version }}
@@ -71,7 +71,7 @@ jobs:
 
     strategy:
       matrix:
-        ruby-version: ['3.1', '3.2', '3.3', '3.4.0-preview2']
+        ruby-version: ['3.1', '3.2', '3.3', '3.4']
 
     name: macOS, Ruby ${{ matrix.ruby-version }}
     steps: