diff --git a/projects/rubygems.org/package.yml b/projects/rubygems.org/package.yml
index d236e059..f1aab29d 100644
--- a/projects/rubygems.org/package.yml
+++ b/projects/rubygems.org/package.yml
@@ -15,6 +15,7 @@ runtime:
 build:
   dependencies:
     gnu.org/patch: '*'
+    ruby-lang.org: ~3.1 # testing a theory
   script:
     - ruby setup.rb
       --prefix={{prefix}}