diff --git a/test/reline/helper.rb b/test/reline/helper.rb
index fb2262e7f5..4d0c883c86 100644
--- a/test/reline/helper.rb
+++ b/test/reline/helper.rb
@@ -4,6 +4,7 @@
 
 require 'reline'
 require 'test/unit'
+require 'test/unit/rr'
 
 begin
   require 'rbconfig'
diff --git a/test/reline/test_face.rb b/test/reline/test_face.rb
index 14da4f6d65..f4a56abe0a 100644
--- a/test/reline/test_face.rb
+++ b/test/reline/test_face.rb
@@ -160,7 +160,14 @@ def test_invalid_rgb?
       assert_equal false, @config.send(:rgb_expression?, "#FFFFF")
     end
 
-    def test_format_to_sgr_preserves_order
+    def test_define_method_proxies_the_order_of_arguments
+      mock(@config).format_to_sgr(
+        [[:foreground, :blue], [:style, [:bold, :italicized]], [:background, :red]]
+      )
+      @config.define :default, foreground: :blue, style: [:bold, :italicized], background: :red
+    end
+
+    def test_format_to_sgr_preserves_order_of_values
       assert_equal(
         "#{RESET_SGR}\e[37;41;1;3m",
         @config.send(:format_to_sgr, foreground: :white, background: :red, style: [:bold, :italicized])