diff --git a/Gemfile b/Gemfile
index e673971..39549fe 100644
--- a/Gemfile
+++ b/Gemfile
@@ -4,4 +4,4 @@ gemspec
 
 gem "rake"
 gem "test-unit"
-gem "test-unit-ruby-core", git: "https://github.com/ruby/test-unit-ruby-core"
+gem "test-unit-ruby-core"