diff --git a/pyas2lib/as2.py b/pyas2lib/as2.py
index d81fa1d..460ec82 100644
--- a/pyas2lib/as2.py
+++ b/pyas2lib/as2.py
@@ -381,7 +381,9 @@ def build(
             self.message_id = f"{message_id}@{self.sender.domain}"
         else:
             self.message_id = (
-                email_utils.make_msgid(domain=self.sender.domain).lstrip("<").rstrip(">")
+                email_utils.make_msgid(domain=self.sender.domain)
+                .lstrip("<")
+                .rstrip(">")
             )
 
         # ensure the total length of the message id is no more than 255 characters
diff --git a/pyas2lib/tests/test_basic.py b/pyas2lib/tests/test_basic.py
index aac10fc..fed94b9 100644
--- a/pyas2lib/tests/test_basic.py
+++ b/pyas2lib/tests/test_basic.py
@@ -219,7 +219,10 @@ def test_invalid_message_id_length_raises_error(self):
         very_long_message_id = "a" * 1000
         with pytest.raises(ValueError) as excinfo:
             out_message.build(self.test_data, message_id=very_long_message_id)
-        assert "Message ID must be no more than 255 characters for compatibility" in str(excinfo.value)
+        assert (
+            "Message ID must be no more than 255 characters for compatibility"
+            in str(excinfo.value)
+        )
 
     def find_org(self, as2_id):
         return self.org