diff --git a/network_server.h b/network_server.h
--- a/network_server.h
+++ b/network_server.h
@@ -14,6 +14,7 @@ void NetworkServer_HandleChat(NetworkAct
 
 bool NetworkServer_ReadPackets(ClientState *cs);
 void NetworkServer_Tick();
+void NetworkServerMonthlyLoop();
 
 #endif /* ENABLE_NETWORK */