diff --git a/railties/lib/rails/generators/rails/app/templates/Gemfile b/railties/lib/rails/generators/rails/app/templates/Gemfile
index 422217286c..f1015b16d5 100644
--- a/railties/lib/rails/generators/rails/app/templates/Gemfile
+++ b/railties/lib/rails/generators/rails/app/templates/Gemfile
@@ -1,5 +1,10 @@
 source 'https://rubygems.org'
 
+git_source(:github) do |repo_name|
+  repo_name = "#{repo_name}/#{repo_name}" unless repo_name.include?("/")
+  "https://github.com/#{repo_name}.git"
+end
+
 <% gemfile_entries.each do |gem| -%>
 <% if gem.comment -%>