diff --git a/lib/credit_card_gateway.rb b/lib/credit_card_gateway.rb
index 842e8e7cae7f0fc32a27a3335948603e0b986eec..846659d149eb79d4eed95b6979ca3194995b969c 100644
--- a/lib/credit_card_gateway.rb
+++ b/lib/credit_card_gateway.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 require "braintree"
-require "customer"
+require_relative "customer"
 
 class CreditCardGateway
 	class ErrorResult < StandardError