diff --git a/Gemfile b/Gemfile
index 948af2ee..b2ede2ec 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-source 'https://17.3.alpine.gems.sutty.nl'
+source ENV.fetch('GEMS_SOURCE', 'https://17.3.alpine.gems.sutty.nl')
 
 ruby "~> #{ENV.fetch('RUBY_VERSION', '3.1')}"