diff --git a/telethon/network/mtprotosender.py b/telethon/network/mtprotosender.py
index 4a3a38b7..cf19ecb4 100644
--- a/telethon/network/mtprotosender.py
+++ b/telethon/network/mtprotosender.py
@@ -611,7 +611,7 @@ class MTProtoSender:
         bad_msg = message.obj
         msg = self._pending_messages.get(bad_msg.bad_msg_id)
 
-        __log__.debug('Handling bad msg for message %d', bad_msg.bad_msg_id)
+        __log__.debug('Handling bad msg %s', bad_msg)
         if bad_msg.error_code in (16, 17):
             # Sent msg_id too low or too high (respectively).
             # Use the current msg_id to determine the right time offset.
diff --git a/telethon/network/mtprotostate.py b/telethon/network/mtprotostate.py
index 6ea13ae2..e7bde1de 100644
--- a/telethon/network/mtprotostate.py
+++ b/telethon/network/mtprotostate.py
@@ -157,10 +157,20 @@ class MTProtoState:
         Updates the time offset to the correct
         one given a known valid message ID.
         """
+        bad = self._get_new_msg_id()
+        old = self.time_offset
+
         now = int(time.time())
         correct = correct_msg_id >> 32
         self.time_offset = correct - now
-        self._last_msg_id = 0
+
+        if self.time_offset != old:
+            self._last_msg_id = 0
+            __log__.debug(
+                'Updated time offset (old offset %d, bad %d, good %d, new %d)',
+                old, bad, correct_msg_id, self.time_offset
+            )
+
         return self.time_offset
 
     def _get_seq_no(self, content_related):