diff --git a/agent/sim/core.h b/agent/sim/core.h
index c11eecf..5d95997 100644
--- a/agent/sim/core.h
+++ b/agent/sim/core.h
@@ -37,7 +37,7 @@
 Status EnableUplinkIf_(uint32_t intf_id);
 Status DisableUplinkIf_(uint32_t intf_id);
 Status OmciMsgOut_(uint32_t intf_id, uint32_t onu_id, const std::string pkt);
-Status OnuPacketOut_(uint32_t intf_id, uint32_t onu_id, uint64_t cookie, const std::string pkt);
+Status OnuPacketOut_(uint32_t intf_id, uint32_t onu_id, uint32_t port_no, const std::string pkt);
 Status UplinkPacketOut_(uint32_t intf_id, const std::string pkt);
 Status FlowAdd_(int32_t access_intf_id, int32_t onu_id, int32_t uni_id, uint32_t port_no,
                 uint32_t flow_id, const std::string flow_type,