Index: head/sys/netinet/ip_output.c
===================================================================
--- head/sys/netinet/ip_output.c
+++ head/sys/netinet/ip_output.c
@@ -145,7 +145,8 @@
 	if (inp != NULL) {
 		INP_LOCK_ASSERT(inp);
 		M_SETFIB(m, inp->inp_inc.inc_fibnum);
-		if (inp->inp_flags & (INP_HW_FLOWID|INP_SW_FLOWID)) {
+		if (((flags & IP_NODEFAULTFLOWID) == 0) &&
+		    inp->inp_flags & (INP_HW_FLOWID|INP_SW_FLOWID)) {
 			m->m_pkthdr.flowid = inp->inp_flowid;
 			M_HASHTYPE_SET(m, inp->inp_flowtype);
 			m->m_flags |= M_FLOWID;
Index: head/sys/netinet/ip_var.h
===================================================================
--- head/sys/netinet/ip_var.h
+++ head/sys/netinet/ip_var.h
@@ -161,6 +161,7 @@
 #define	IP_SENDTOIF		0x8		/* send on specific ifnet */
 #define IP_ROUTETOIF		SO_DONTROUTE	/* 0x10 bypass routing tables */
 #define IP_ALLOWBROADCAST	SO_BROADCAST	/* 0x20 can send broadcast packets */
+#define	IP_NODEFAULTFLOWID	0x40		/* Don't set the flowid from inp */
 
 #ifdef __NO_STRICT_ALIGNMENT
 #define IP_HDR_ALIGNED_P(ip)	1