diff --git a/mautrix_telegram/bot.py b/mautrix_telegram/bot.py
index 0a6e71a4..5e29a5b2 100644
--- a/mautrix_telegram/bot.py
+++ b/mautrix_telegram/bot.py
@@ -65,6 +65,12 @@ class Bot(AbstractUser):
             except (ChannelPrivateError, ChannelInvalidError):
                 self.remove_chat(id.channel_id)
 
+    def register_portal(self, portal):
+        self.add_chat(portal.tgid, portal.peer_type)
+
+    def unregister_portal(self, portal):
+        self.remove_chat(portal.tgid)
+
     def add_chat(self, id, type):
         if id not in self.chats:
             self.chats[id] = type
diff --git a/mautrix_telegram/db.py b/mautrix_telegram/db.py
index 81829c7a..4f48412c 100644
--- a/mautrix_telegram/db.py
+++ b/mautrix_telegram/db.py
@@ -112,7 +112,7 @@ class TelegramFile(Base):
     mxc = Column(String)
     mime_type = Column(String)
     was_converted = Column(Boolean)
-    timestamp = Column(BigInteger, primary_key=True)
+    timestamp = Column(BigInteger)
 
 
 def init(db_session):
diff --git a/mautrix_telegram/portal.py b/mautrix_telegram/portal.py
index 858c3a9a..22e5e519 100644
--- a/mautrix_telegram/portal.py
+++ b/mautrix_telegram/portal.py
@@ -491,8 +491,11 @@ class Portal:
         if self.peer_type == "user":
             await self.main_intent.leave_room(self.mxid)
             self.delete()
-            del self.by_tgid[self.tgid_full]
-            del self.by_mxid[self.mxid]
+            try:
+                del self.by_tgid[self.tgid_full]
+                del self.by_mxid[self.mxid]
+            except KeyError:
+                pass
         elif source and source.tgid != user.tgid:
             if self.peer_type == "chat":
                 await source.client(DeleteChatUserRequest(chat_id=self.tgid, user_id=user.tgid))
diff --git a/mautrix_telegram/util/file_transfer.py b/mautrix_telegram/util/file_transfer.py
index 698cb874..76e113b3 100644
--- a/mautrix_telegram/util/file_transfer.py
+++ b/mautrix_telegram/util/file_transfer.py
@@ -44,7 +44,7 @@ def _convert_webp(file, to="png"):
 async def transfer_file_to_matrix(db, client, intent, location):
     if isinstance(location, (Document, InputDocumentFileLocation)):
         id = f"{location.id}-{location.version}"
-    elif not isinstance(location, (FileLocation, InputFileLocation)):
+    elif isinstance(location, (FileLocation, InputFileLocation)):
         id = f"{location.volume_id}-{location.local_id}"
     else:
         return None