2 files changed, 4 insertions, 4 deletions

diff --git a/src/mailman/utilities/importer.py b/src/mailman/utilities/importer.py
index 9eb0fdf35..03ac94870 100644
--- a/src/mailman/utilities/importer.py
+++ b/src/mailman/utilities/importer.py
@@ -175,7 +175,6 @@ TYPES = dict(
 
 # Attribute names in Mailman 2 which are renamed in Mailman 3.
 NAME_MAPPINGS = dict(
-    host_name='mail_host',
     include_list_post_header='allow_list_posts',
     real_name='display_name',
     last_post_time='last_post_at',
diff --git a/src/mailman/utilities/tests/test_import.py b/src/mailman/utilities/tests/test_import.py
index 23cf74b36..76c8174d5 100644
--- a/src/mailman/utilities/tests/test_import.py
+++ b/src/mailman/utilities/tests/test_import.py
@@ -77,11 +77,12 @@ class TestBasicImport(unittest.TestCase):
         self._import()
         self.assertEqual(self._mlist.display_name, 'Test')
 
-    def test_mail_host(self):
-        # The mlist.mail_host gets set.
+    def test_mail_host_invariant(self):
+        # The mlist.mail_host must not be updated when importing (it will
+        # change the list_id property, which is supposed to be read-only)
         self.assertEqual(self._mlist.mail_host, 'example.com')
         self._import()
-        self.assertEqual(self._mlist.mail_host, 'heresy.example.org')
+        self.assertEqual(self._mlist.mail_host, 'example.com')
 
     def test_rfc2369_headers(self):
         self._mlist.allow_list_posts = False