diff --git a/tests/runtests.py b/tests/runtests.py
index c9097d5a..6972d798 100644
--- a/tests/runtests.py
+++ b/tests/runtests.py
@@ -40,6 +40,7 @@
 import threading
 import time
 import unittest
+import urllib.error
 import warnings
 import xml.sax
 import zlib
@@ -404,6 +405,12 @@ def test_unicode_2(self):
         r = feedparser.api._open_resource(s, '', '', '', '', [], {}, {})
         self.assertEqual(s, r)
 
+    def test_http_client_ascii_unicode_encode_error(self):
+        """Confirm that a Unicode character doesn't cause a UnicodeEncodeError crash."""
+        url = 'https://0.0.0.0/ô'
+        with self.assertRaises(urllib.error.URLError):
+            feedparser.api._open_resource(url, '', '', '', '', [], {}, {})
+
 
 def make_safe_uri_test(rel, expect, doc):
     def fn(self):