diff --git a/Gemfile b/Gemfile
index bbece7773..5b23e0ce9 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,4 @@
-source "https://rubygems.org"
+source ENV.fetch("RUBY_GEMS_MIRROR", "https://rubygems.org")
 
 gem 'bosh-template'
 gem 'rspec'