diff --git a/src/matrix_bot/client.py b/src/matrix_bot/client.py
index c4a5b0b..693802b 100644
--- a/src/matrix_bot/client.py
+++ b/src/matrix_bot/client.py
@@ -60,15 +60,13 @@ class Client(Aobject):
         if isinstance(resp, nio.responses.LoginError):
             raise RuntimeError(f"Fail to connect: {resp.message}")
 
-        # TODO: Where is the async map when you need it?
         self.allowed_rooms = None
         if allowed_rooms_names:
             self.allowed_rooms = {}
-            for room_name in allowed_rooms_names:
-                room = await self.resolve_room(room_name)
+            rooms = await asyncio.gather(*(self.resolve_room(room_name) for room_name in allowed_rooms_names))
+            for room in rooms:
                 self.allowed_rooms[room.id] = room # room uniqueness is handled by self.resolve_room
 
-
     async def resolve_room(
         self,
         room_name: Union[RoomAlias, RoomId]
@@ -86,7 +84,9 @@ class Client(Aobject):
             return self.__rooms_by_id[room_name]
         # If it is a unknown room id:
         elif room_name[0] == '!':
-            return Room(id=room_name)
+            room = Room(id=room_name)
+            self.__rooms_by_id[room_name] = room
+            return room
         # If it is not a room id nor a room alias:
         elif room_name[0] != '#':
             raise ValueError(f"Invalid room_name: {room_name}")
@@ -122,7 +122,6 @@ class Client(Aobject):
             if isinstance(sync_resp, nio.responses.SyncError):
                 print(f"Error while syncronizing: {sync_resp.message}") # TODO: use proper logging
                 continue
-            print(sync_resp)
 
     async def run(
         self,
diff --git a/tests/test.py b/tests/test.py
index 1aea0f0..765db95 100644
--- a/tests/test.py
+++ b/tests/test.py
@@ -16,7 +16,7 @@ async def main():
         os.environ["PASSWD"],
         os.environ["ROOMS"].split(",")
     )
-#    print(client.allowed_rooms)
+    print(client.allowed_rooms)
     await client.run()