diff --git a/Gemfile b/Gemfile
index 47e44b9d..1c86b4cd 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,4 @@
-source :rubygems
+source 'https://rubygems.org'
 
 # Make sure to use Haml 4 for tests
 gem "haml", "~> 4.0.0"