DEFINE_FIELD (OF_ARP_OP, FWW_NW_PROTO, ETH_TYPE_ARP, 0, false)
DEFINE_FIELD_M(OF_ARP_SPA, 0, ETH_TYPE_ARP, 0, false)
DEFINE_FIELD_M(OF_ARP_TPA, 0, ETH_TYPE_ARP, 0, false)
-DEFINE_FIELD (NX_TUN_ID, FWW_TUN_ID, 0, 0, true)
+DEFINE_FIELD_M(NX_TUN_ID, 0, 0, 0, true)
DEFINE_FIELD_M(NX_REG0, 0, 0, 0, true)
#if FLOW_N_REGS >= 2