diff --git a/Lib/mailbox.py b/Lib/mailbox.py
index 4a44642765cc9a..cc9e2c37f28d9a 100644
--- a/Lib/mailbox.py
+++ b/Lib/mailbox.py
@@ -1224,6 +1224,7 @@ def get_sequences(self):
         with f:
             all_keys = set(self.keys())
             for line in f:
+                line = line.rstrip()
                 try:
                     name, contents = line.split(':')
                     keys = set()
@@ -1239,7 +1240,7 @@ def get_sequences(self):
                         del results[name]
                 except ValueError:
                     raise FormatError('Invalid sequence specification: %s' %
-                                      line.rstrip())
+                                      line)
         return results
 
     def set_sequences(self, sequences):
@@ -1291,7 +1292,7 @@ def pack(self):
         self._next_key = prev + 1
         if len(changes) == 0:
             return
-        for name, key_list in sequences.items():
+        for key_list in sequences.values():
             for old, new in changes:
                 if old in key_list:
                     key_list[key_list.index(old)] = new
diff --git a/Lib/test/test_mailbox.py b/Lib/test/test_mailbox.py
index 288b2c4496faa1..f22728db3ab14a 100644
--- a/Lib/test/test_mailbox.py
+++ b/Lib/test/test_mailbox.py
@@ -1377,6 +1377,11 @@ def test_sequences(self):
         msg0 = mailbox.MHMessage(self._template % 0)
         msg0.add_sequence('foo')
         key0 = self._box.add(msg0)
+        msg = self._box.get_message(key0)
+        self.assertEqual(len(msg.get_sequences()), 1)
+        self.assertEqual(msg.get_sequences()[0], 'foo')
+        self.assertEqual(msg['from'], 'foo')
+        self.assertEqual(msg.get_payload(), '0\n')
         self.assertEqual(self._box.get_sequences(), {'foo':[key0]})
         msg1 = mailbox.MHMessage(self._template % 1)
         msg1.set_sequences(['bar', 'replied', 'foo'])