diff --git a/CHANGELOG b/CHANGELOG
index 09c3be034..3f9b055e7 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,12 @@
 # Nmap Changelog ($Id$); -*-text-*-
 
+o Fixed an assertion failure with IPv6 traceroute trying to use an
+  unsupported protocol:
+    nmap: traceroute.cc:749: virtual unsigned char*
+    UDPProbe::build_packet(const sockaddr_storage*, u32*) const: Assertion
+    `source->ss_family == 2' failed.
+  This was reported by Pierre Emeriaud. [David Fifield]
+
 o [NSE] Added oracle-brute-stealth which exploits CVE-2012-3137, a weakness
   in the Oracle O5LOGIN authentication scheme. [Dhiru Kholia]
 
diff --git a/traceroute.cc b/traceroute.cc
index 33fa5b351..d0351c248 100644
--- a/traceroute.cc
+++ b/traceroute.cc
@@ -555,10 +555,13 @@ struct probespec HostState::get_probe(const Target *target) {
   struct probespec probe;
 
   probe = target->pingprobe;
-  if (probe.type == PS_TCP || probe.type == PS_UDP || probe.type == PS_ICMP ||
-      probe.type == PS_SCTP || probe.type == PS_ICMPV6) {
+  if (target->af() == AF_INET &&
+      (probe.type == PS_TCP || probe.type == PS_UDP || probe.type == PS_SCTP || probe.type == PS_ICMP)) {
     /* Nothing needed. */
-  } else if (probe.type == PS_PROTO) {
+  } else if (target->af() == AF_INET6 &&
+      (probe.type == PS_TCP || probe.type == PS_ICMPV6)) {
+    /* Nothing needed. */
+  } else if (target->af() == AF_INET && probe.type == PS_PROTO) {
     /* If this is an IP protocol probe, fill in some fields for some common
        protocols. We cheat and store them in the TCP-, UDP-, SCTP- and
        ICMP-specific fields. */