diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index ef2d8d2a..a38756b6 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -50,7 +50,7 @@ jobs:
       - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803 # v6
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: "4.0.5"
+          ruby-version: "4.0.6"
       - run: bundle install
       - name: Standard
         run: bundle exec rake standard
@@ -63,7 +63,7 @@ jobs:
           submodules: true
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: "4.0.5"
+          ruby-version: "4.0.6"
       - run: bundle install
       - name: Cucumber
         run: bundle exec cucumber
@@ -74,7 +74,7 @@ jobs:
       - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803 # v6
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: "4.0.5"
+          ruby-version: "4.0.6"
       - run: bundle install
       - run: bundle exec rbs collection install
       - run: bundle exec steep check
@@ -85,7 +85,7 @@ jobs:
       - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803 # v6
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: "4.0.5"
+          ruby-version: "4.0.6"
       - name: Bundle Audit
         run: bundle lock && gem install bundler-audit && bundle-audit check --update
   # check the status of other jobs, so we can have a single job dependency for branch protection
diff --git a/.ruby-version b/.ruby-version
index 7636e756..d13e837c 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-4.0.5
+4.0.6
diff --git a/.tool-versions b/.tool-versions
index aac7389b..05913eae 100644
--- a/.tool-versions
+++ b/.tool-versions
@@ -1 +1 @@
-ruby 4.0.5
+ruby 4.0.6