diff --git a/test/rubygems/helper.rb b/test/rubygems/helper.rb
index 9f4dc6616b..a9c1438272 100644
--- a/test/rubygems/helper.rb
+++ b/test/rubygems/helper.rb
@@ -20,7 +20,7 @@ require "tmpdir"
 require "uri"
 require "zlib"
 require "benchmark" # stdlib
-require "rubygems/mock_gem_ui"
+require_relative "mock_gem_ui"
 
 module Gem
   ##
diff --git a/lib/rubygems/mock_gem_ui.rb b/test/rubygems/mock_gem_ui.rb
similarity index 97%
rename from lib/rubygems/mock_gem_ui.rb
rename to test/rubygems/mock_gem_ui.rb
index b839f8987b..1ece78fde7 100644
--- a/lib/rubygems/mock_gem_ui.rb
+++ b/test/rubygems/mock_gem_ui.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require_relative "user_interaction"
+require "rubygems/user_interaction"
 
 ##
 # This Gem::StreamUI subclass records input and output to StringIO for