diff --git a/telethon/events/chataction.py b/telethon/events/chataction.py
index 6649957f..cf6faae5 100644
--- a/telethon/events/chataction.py
+++ b/telethon/events/chataction.py
@@ -272,8 +272,8 @@ class ChatAction(EventBuilder):
             """
             Returns the marked signed ID of the first user, if any.
             """
-            if self.input_users:
-                return utils.get_peer_id(self._input_users[0])
+            if self._user_peers:
+                return utils.get_peer_id(self._user_peers[0])
 
         @property
         def users(self):
@@ -325,5 +325,5 @@ class ChatAction(EventBuilder):
             """
             Returns the marked signed ID of the users, if any.
             """
-            if self.input_users:
-                return [utils.get_peer_id(u) for u in self._input_users]
+            if self._user_peers:
+                return [utils.get_peer_id(u) for u in self._user_peers]
diff --git a/telethon/events/newmessage.py b/telethon/events/newmessage.py
index d443909a..f6761485 100644
--- a/telethon/events/newmessage.py
+++ b/telethon/events/newmessage.py
@@ -263,8 +263,7 @@ class NewMessage(EventBuilder):
             """
             Returns the marked sender integer ID, if present.
             """
-            if self.input_sender:
-                return utils.get_peer_id(self._input_sender)
+            return self.message.from_id
 
         @property
         def text(self):