diff --git a/Lib/email/test/test_email.py b/Lib/email/test/test_email.py
index 8950e0d17a7..280b400161c 100644
--- a/Lib/email/test/test_email.py
+++ b/Lib/email/test/test_email.py
@@ -841,6 +841,22 @@ def test_another_long_multiline_header(self):
 
 ''')
 
+    def test_long_lines_with_different_header(self):
+        eq = self.ndiffAssertEqual
+        h = """\
+List-Unsubscribe: <https://lists.sourceforge.net/lists/listinfo/spamassassin-talk>,
+        <mailto:spamassassin-talk-request@lists.sourceforge.net?subject=unsubscribe>"""
+        msg = Message()
+        msg['List'] = h
+        msg['List'] = Header(h, header_name='List')
+        eq(msg.as_string(), """\
+List: List-Unsubscribe: <https://lists.sourceforge.net/lists/listinfo/spamassassin-talk>,
+	<mailto:spamassassin-talk-request@lists.sourceforge.net?subject=unsubscribe>
+List: List-Unsubscribe: <https://lists.sourceforge.net/lists/listinfo/spamassassin-talk>,
+ <mailto:spamassassin-talk-request@lists.sourceforge.net?subject=unsubscribe>
+
+""")
+
 
 
 # Test mangling of "From " lines in the body of a message