diff --git a/Lib/test/test_unicode.py b/Lib/test/test_unicode.py
index c63364a..b20f878 100644
--- a/Lib/test/test_unicode.py
+++ b/Lib/test/test_unicode.py
@@ -1824,6 +1824,12 @@
                          b'123&#8364;')
         self.assertEqual(unicode_encodedecimal("123\u20ac", "backslashreplace"),
                          b'123\\u20ac')
+        self.assertEqual(unicode_encodedecimal("123\u20ac\N{EM SPACE}", "replace"),
+                         b'123? ')
+        self.assertEqual(unicode_encodedecimal("123\u20ac\u20ac", "replace"),
+                         b'123??')
+        self.assertEqual(unicode_encodedecimal("123\u20ac\u0660", "replace"),
+                         b'123?0')
 
     def test_transform_decimal(self):
         from _testcapi import unicode_transformdecimaltoascii as transform_decimal