diff --git a/lib/bundler/vendor/pub_grub/lib/pub_grub/static_package_source.rb b/lib/bundler/vendor/pub_grub/lib/pub_grub/static_package_source.rb
index 4bf61461b2..36ab06254d 100644
--- a/lib/bundler/vendor/pub_grub/lib/pub_grub/static_package_source.rb
+++ b/lib/bundler/vendor/pub_grub/lib/pub_grub/static_package_source.rb
@@ -1,4 +1,5 @@
 require_relative 'package'
+require_relative 'rubygems'
 require_relative 'version_constraint'
 require_relative 'incompatibility'
 require_relative 'basic_package_source'