diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 412d4d5..91fb2f8 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -26,7 +26,7 @@ jobs:
           persist-credentials: false
       - uses: ruby/setup-ruby@6aaa311d81eba98ae12eaffbcb63296ace0efcde # v1
         with:
-          ruby-version: "3.4"
+          ruby-version: "4.0"
           bundler-cache: true
       - name: Resolve release metadata
         id: meta
@@ -81,7 +81,7 @@ jobs:
           persist-credentials: false
       - uses: ruby/setup-ruby@6aaa311d81eba98ae12eaffbcb63296ace0efcde # v1
         with:
-          ruby-version: "3.4"
+          ruby-version: "4.0"
           bundler-cache: true
       - uses: rubygems/release-gem@7f9650160c1a4e7989fdc9855807bdbd421d8b6b # v1.4.1
 
diff --git a/Dockerfile b/Dockerfile
index a1bd342..559722a 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM ruby:3.4
+FROM ruby:4.0
 RUN apt-get update -qq && apt-get install -y build-essential libpq-dev
 
 RUN mkdir -p /app