--- sys/netinet/ip_output.c.orig	2016-09-05 01:41:12.445263000 +0700
+++ sys/netinet/ip_output.c	2016-09-07 18:20:56.306433000 +0700
@@ -873,6 +873,12 @@ smart_frag_failure:
 			goto done;
 		}
 		m->m_pkthdr.len = mhlen + len;
+
+ 		if (M_HASHTYPE_GET(m0) != M_HASHTYPE_NONE) {
+ 			m->m_pkthdr.flowid = m0->m_pkthdr.flowid;
+ 			M_HASHTYPE_SET(m, M_HASHTYPE_GET(m0));
+ 		}
+
 #ifdef MAC
 		mac_netinet_fragment(m0, m);
 #endif