diff --git a/telethon/events/newmessage.py b/telethon/events/newmessage.py
index c15b9700..dc40ca11 100644
--- a/telethon/events/newmessage.py
+++ b/telethon/events/newmessage.py
@@ -156,7 +156,7 @@ class NewMessage(EventBuilder):
                 return
 
         if self.from_users is not None:
-            if utils.get_peer_id(event.message.from_id) not in self.from_users:
+            if event.message.sender_id not in self.from_users:
                 return
 
         if self.pattern:
diff --git a/telethon/tl/custom/forward.py b/telethon/tl/custom/forward.py
index c808de1d..a95eae30 100644
--- a/telethon/tl/custom/forward.py
+++ b/telethon/tl/custom/forward.py
@@ -31,9 +31,7 @@ class Forward(ChatGetter, SenderGetter):
         self.original_fwd = original
 
         sender_id = sender = input_sender = peer = chat = input_chat = None
-        if not original.from_id:
-            pass
-        else:
+        if original.from_id:
             ty = helpers._entity_type(original.from_id)
             if ty == helpers._EntityType.USER:
                 sender_id = utils.get_peer_id(original.from_id)