diff --git a/[refs] b/[refs]
index 0747381da2c6..f20bf70969db 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 37bc4f8dfa72fb43b84381abca39cfdbbc8ff2df
+refs/heads/master: 409b545ac10d9548929557a75ad86540f59a2c83
diff --git a/trunk/net/netfilter/xt_TCPMSS.c b/trunk/net/netfilter/xt_TCPMSS.c
index a75240f0d42b..afaebc766933 100644
--- a/trunk/net/netfilter/xt_TCPMSS.c
+++ b/trunk/net/netfilter/xt_TCPMSS.c
@@ -125,6 +125,12 @@ tcpmss_mangle_packet(struct sk_buff *skb,
 
 	skb_put(skb, TCPOLEN_MSS);
 
+	/* RFC 879 states that the default MSS is 536 without specific
+	 * knowledge that the destination host is prepared to accept larger.
+	 * Since no MSS was provided, we MUST NOT set a value > 536.
+	 */
+	newmss = min(newmss, (u16)536);
+
 	opt = (u_int8_t *)tcph + sizeof(struct tcphdr);
 	memmove(opt + TCPOLEN_MSS, opt, tcplen - sizeof(struct tcphdr));