diff --git a/corres2math/matrix.py b/corres2math/matrix.py
index d01e44f..a6265a9 100644
--- a/corres2math/matrix.py
+++ b/corres2math/matrix.py
@@ -216,7 +216,7 @@ class Matrix:
         """
         client = await cls._get_client()
         resp = await client.room_resolve_alias(room_alias)
-        return resp.room_id if resp else None
+        return resp.room_id if resp and hasattr(resp, "room_id") else None
 
     @classmethod
     @async_to_sync