diff --git a/.github/workflows/codesee-arch-diagram.yml b/.github/workflows/codesee-arch-diagram.yml
index c025fc4..71c0516 100644
--- a/.github/workflows/codesee-arch-diagram.yml
+++ b/.github/workflows/codesee-arch-diagram.yml
@@ -49,7 +49,7 @@ jobs:
         uses: ruby/setup-ruby@v1
         if: ${{ fromJSON(steps.detect-languages.outputs.languages).ruby }}
         with:
-          ruby-version: '3.0'
+          ruby-version: '4.0.0'
 
       # CodeSee Maps Rust support uses a static binary so there's no setup step required.