diff --git a/include/linux/pfkeyv2.h b/include/linux/pfkeyv2.h
index e6b5192..7240667 100644
--- a/include/linux/pfkeyv2.h
+++ b/include/linux/pfkeyv2.h
@@ -245,6 +245,7 @@
 
 /* Security Association flags */
 #define SADB_SAFLAGS_PFS	1
+#define SADB_SAFLAGS_NOPMTUDISC	0x20000000
 #define SADB_SAFLAGS_DECAP_DSCP	0x40000000
 #define SADB_SAFLAGS_NOECN	0x80000000
 
diff --git a/include/linux/xfrm.h b/include/linux/xfrm.h
index d68391a..f0d4233 100644
--- a/include/linux/xfrm.h
+++ b/include/linux/xfrm.h
@@ -196,6 +196,7 @@
 	__u8				flags;
 #define XFRM_STATE_NOECN	1
 #define XFRM_STATE_DECAP_DSCP	2
+#define XFRM_STATE_NOPMTUDISC	4
 };
 
 struct xfrm_usersa_id {
diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c
index af2392a..66620a9 100644
--- a/net/ipv4/xfrm4_output.c
+++ b/net/ipv4/xfrm4_output.c
@@ -33,6 +33,7 @@
 	struct dst_entry *dst = skb->dst;
 	struct xfrm_state *x = dst->xfrm;
 	struct iphdr *iph, *top_iph;
+	int flags;
 
 	iph = skb->nh.iph;
 	skb->h.ipiph = iph;
@@ -51,10 +52,13 @@
 
 	/* DS disclosed */
 	top_iph->tos = INET_ECN_encapsulate(iph->tos, iph->tos);
-	if (x->props.flags & XFRM_STATE_NOECN)
+
+	flags = x->props.flags;
+	if (flags & XFRM_STATE_NOECN)
 		IP_ECN_clear(top_iph);
 
-	top_iph->frag_off = iph->frag_off & htons(IP_DF);
+	top_iph->frag_off = (flags & XFRM_STATE_NOPMTUDISC) ?
+		0 : (iph->frag_off & htons(IP_DF));
 	if (!top_iph->frag_off)
 		__ip_select_ident(top_iph, dst, 0);
 
diff --git a/net/ipv4/xfrm4_state.c b/net/ipv4/xfrm4_state.c
index 223a2e8..050611d 100644
--- a/net/ipv4/xfrm4_state.c
+++ b/net/ipv4/xfrm4_state.c
@@ -7,12 +7,20 @@
  *
  */
 
+#include <net/ip.h>
 #include <net/xfrm.h>
 #include <linux/pfkeyv2.h>
 #include <linux/ipsec.h>
 
 static struct xfrm_state_afinfo xfrm4_state_afinfo;
 
+static int xfrm4_init_flags(struct xfrm_state *x)
+{
+	if (ipv4_config.no_pmtu_disc)
+		x->props.flags |= XFRM_STATE_NOPMTUDISC;
+	return 0;
+}
+
 static void
 __xfrm4_init_tempsel(struct xfrm_state *x, struct flowi *fl,
 		     struct xfrm_tmpl *tmpl,
@@ -109,6 +117,7 @@
 static struct xfrm_state_afinfo xfrm4_state_afinfo = {
 	.family			= AF_INET,
 	.lock			= RW_LOCK_UNLOCKED,
+	.init_flags		= xfrm4_init_flags,
 	.init_tempsel		= __xfrm4_init_tempsel,
 	.state_lookup		= __xfrm4_state_lookup,
 	.find_acq		= __xfrm4_find_acq,
diff --git a/net/key/af_key.c b/net/key/af_key.c
index 652dd09..4879743 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -690,6 +690,8 @@
 		sa->sadb_sa_flags |= SADB_SAFLAGS_NOECN;
 	if (x->props.flags & XFRM_STATE_DECAP_DSCP)
 		sa->sadb_sa_flags |= SADB_SAFLAGS_DECAP_DSCP;
+	if (x->props.flags & XFRM_STATE_NOPMTUDISC)
+		sa->sadb_sa_flags |= SADB_SAFLAGS_NOPMTUDISC;
 
 	/* hard time */
 	if (hsc & 2) {
@@ -974,6 +976,8 @@
 		x->props.flags |= XFRM_STATE_NOECN;
 	if (sa->sadb_sa_flags & SADB_SAFLAGS_DECAP_DSCP)
 		x->props.flags |= XFRM_STATE_DECAP_DSCP;
+	if (sa->sadb_sa_flags & SADB_SAFLAGS_NOPMTUDISC)
+		x->props.flags |= XFRM_STATE_NOPMTUDISC;
 
 	lifetime = (struct sadb_lifetime*) ext_hdrs[SADB_EXT_LIFETIME_HARD-1];
 	if (lifetime != NULL) {