diff --git a/test/card_test.rb b/test/card_test.rb
index 4351089..fdd3194 100644
--- a/test/card_test.rb
+++ b/test/card_test.rb
@@ -1,3 +1,4 @@
+# encoding: UTF-8
 require_relative 'test_helper'
 
 class CardTest < Minitest::Test