diff --git a/callbacks.py b/callbacks.py
index 4b82768..b96b24c 100644
--- a/callbacks.py
+++ b/callbacks.py
@@ -76,3 +76,7 @@ async def file_cb(room: MatrixRoom, event: RoomMessageFile) -> None:
 
         with open(os.path.join(directory, filename), 'wb') as f:
             f.write(response.body)
+
+async def invite_cb(room: MatrixRoom, event: InviteEvent) -> None:
+    import utils
+    await utils.get_client().join(room_id=room.room_id)
diff --git a/lilypond.py b/lilypond.py
index 0054081..7680d18 100644
--- a/lilypond.py
+++ b/lilypond.py
@@ -17,7 +17,7 @@ def render(user: str, source: str, png: bool = True) -> str:
     tmp.write(bytes(fmt, encoding="utf8"))
     tmp.close()
     if png:
-        subprocess.run(["lilypond", "-d", "preview", "--png", tmp.name], cwd="/tmp")
+        subprocess.run(["lilypond", "-d", "preview", "--png", "-dresolution=500", tmp.name], cwd="/tmp")
         return tmp.name + ".preview.png"
 
     subprocess.run(["lilypond", "-d", "preview", "--svg", tmp.name], cwd="/tmp")
diff --git a/main.py b/main.py
index 4d296ea..49d91c4 100644
--- a/main.py
+++ b/main.py
@@ -43,6 +43,7 @@ async def main() -> None:
     utils.set_client(client)
     client.add_event_callback(callbacks.msg_cb, RoomMessageText)
     client.add_event_callback(callbacks.file_cb, RoomMessageFile)
+    client.add_event_callback(callbacks.invite_cb, InviteEvent)
 
     await client.sync_forever(timeout=10000, full_state=True)