diff --git a/Lib/email/test/test_email.py b/Lib/email/test/test_email.py
index 324332b..ef11e17 100644
--- a/Lib/email/test/test_email.py
+++ b/Lib/email/test/test_email.py
@@ -1556,7 +1556,7 @@
         header = make_header(dh)
         eq(str(header),
            'Re: r\xe4ksm\xf6rg\xe5s baz foo bar r\xe4ksm\xf6rg\xe5s')
-        self.ndiffAssertEqual(header.encode(), """\
+        self.ndiffAssertEqual(header.encode(maxlinelen=76), """\
 Re: =?mac-iceland?q?r=8Aksm=9Arg=8Cs?= baz foo bar =?mac-iceland?q?r=8Aksm?=
  =?mac-iceland?q?=9Arg=8Cs?=""")