diff --git a/railties/test/generators/app_generator_test.rb b/railties/test/generators/app_generator_test.rb
index 7d16a7f17db95..2b5e07ff62ec5 100644
--- a/railties/test/generators/app_generator_test.rb
+++ b/railties/test/generators/app_generator_test.rb
@@ -1028,10 +1028,8 @@ def test_bootsnap_with_dev_option
   def test_inclusion_of_ruby_version
     run_generator
 
-    ruby_version = "#{Gem::Version.new(Gem::VERSION) >= Gem::Version.new("3.3.13") ? Gem.ruby_version : RUBY_VERSION}"
-
     assert_file "Dockerfile" do |content|
-      assert_match(/ARG RUBY_VERSION=#{ruby_version}/, content)
+      assert_match(/ARG RUBY_VERSION=#{Gem.ruby_version}/, content)
     end
     assert_file ".ruby-version" do |content|
       if ENV["RBENV_VERSION"]