diff --git a/activesupport/test/core_ext/object/to_query_test.rb b/activesupport/test/core_ext/object/to_query_test.rb
index 21f97cc3fdb..ea919e2c292 100644
--- a/activesupport/test/core_ext/object/to_query_test.rb
+++ b/activesupport/test/core_ext/object/to_query_test.rb
@@ -3,6 +3,7 @@
 require_relative "../../abstract_unit"
 require "active_support/core_ext/object/to_query"
 require "active_support/core_ext/string/output_safety"
+require "uri"
 
 class ToQueryTest < ActiveSupport::TestCase
   def test_simple_conversion