diff --git a/mautrix_telegram/portal.py b/mautrix_telegram/portal.py
index 2024c578..30611bab 100644
--- a/mautrix_telegram/portal.py
+++ b/mautrix_telegram/portal.py
@@ -600,8 +600,9 @@ class Portal:
         if "w" in info and "h" in info:
             attributes.append(DocumentAttributeImageSize(w=info["w"], h=info["h"]))
 
-        return await client.send_file(self.peer, file, mime, caption, attributes,
-                                      file_name, reply_to=reply_to)
+        return await client.send_file(self.peer, file, mime, caption=caption,
+                                      attributes=attributes, file_name=file_name,
+                                      reply_to=reply_to)
 
     async def handle_matrix_message(self, sender, message, event_id):
         client = sender.client if sender.logged_in else self.bot.client
diff --git a/mautrix_telegram/tgclient.py b/mautrix_telegram/tgclient.py
index a57f2504..64ec537e 100644
--- a/mautrix_telegram/tgclient.py
+++ b/mautrix_telegram/tgclient.py
@@ -67,7 +67,7 @@ class MautrixTelegramClient(TelegramClient):
                 mime_type=mime_type or "application/octet-stream",
                 attributes=list(attr_dict.values()))
 
-        request = SendMediaRequest(entity, media, message=caption, entities=entities,
+        request = SendMediaRequest(entity, media, message=caption or "", entities=entities or [],
                                    reply_to_msg_id=reply_to)
         return self._get_response_message(request, await self(request))