diff --git a/test/autolink_test.rb b/test/autolink_test.rb
index 06cd704..2b71935 100644
--- a/test/autolink_test.rb
+++ b/test/autolink_test.rb
@@ -438,4 +438,8 @@ def test_underscore_in_domain
   def test_underscore_in_subdomain
     assert_linked "<a href=\"http://foo_bar.xyz.com\">http://foo_bar.xyz.com</a>", "http://foo_bar.xyz.com"
   end
+
+  def test_regression_84
+    assert_linked "<a href=\"https://www.keepright.atの情報をもとにエラー修正\">https://www.keepright.atの情報をもとにエラー修正</a>", "https://www.keepright.atの情報をもとにエラー修正"
+  end
 end