diff --git a/rcon/battleye/proto.py b/rcon/battleye/proto.py
index 8f686ed..3f8fc83 100644
--- a/rcon/battleye/proto.py
+++ b/rcon/battleye/proto.py
@@ -169,7 +169,6 @@ class ServerMessage(NamedTuple):
 class ServerMessageAck(NamedTuple):
     """An acknowledgement of a message from the server."""
 
-    header: Header
     seq: int
 
     def __bytes__(self):