diff --git a/.circleci/config.yml b/.circleci/config.yml
index b2cfe3d05..cc60149d2 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -8,7 +8,7 @@ executors:
   default:
     resource_class: large
     docker:
-      - image: cimg/ruby:4.0.7-browsers
+      - image: cimg/ruby:4.0.9-browsers
         environment:
           BUNDLE_PATH: vendor/bundle
           PGHOST: 127.0.0.1
diff --git a/.ruby-version b/.ruby-version
index 43beb4001..7919852fe 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-4.0.7
+4.0.9
diff --git a/.tool-versions b/.tool-versions
index a0b7ddeaf..91f34150d 100644
--- a/.tool-versions
+++ b/.tool-versions
@@ -1,4 +1,4 @@
-ruby 4.0.7
+ruby 4.0.9
 nodejs 26.12.1
 postgres 18.6
 pnpm 12.15.0
diff --git a/Dockerfile b/Dockerfile
index 8df7ba242..e6c792940 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM ruby:4.0.7
+FROM ruby:4.0.9
 
 ENV RACK_ENV=production
 ENV RAILS_ENV=production
diff --git a/Gemfile.lock b/Gemfile.lock
index f1b12fb1b..9c9694669 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -492,7 +492,7 @@ DEPENDENCIES
   with_model
 
 RUBY VERSION
-  ruby 4.0.7
+  ruby 4.0.9
 
 BUNDLED WITH
   4.0.23