diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index e10fa93..f235aaa 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -18,6 +18,7 @@ jobs:
           - "3.1"
           - "3.2"
           - "3.3"
+          - "3.4"
     steps:
       - uses: actions/checkout@v4
       - name: Set up Ruby ${{ matrix.ruby-version }}
diff --git a/Dockerfile b/Dockerfile
index 922fbed..c4655d4 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,5 @@
 # https://hub.docker.com/_/ruby
-ARG RUBY_VERSION=3.3
+ARG RUBY_VERSION=3.4
 
 FROM ruby:$RUBY_VERSION-slim-bookworm