diff --git a/CHANGELOG b/CHANGELOG
index 38e3b849a..d93ca96d3 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,8 @@
 # Nmap Changelog ($Id$); -*-text-*-
 
+o Fixed a crash (NULL pointer dereference) in PortList::isTCPwrapped when using
+  -sV and -O on an unknown service not listed in nmap-services. [Pierre Lalet]
+
 o Fixed a benign TOCTOU race between stat() and open() in mmapfile().
   Reported by Camille Mougey. [Henri Doreau]
 
diff --git a/portlist.cc b/portlist.cc
index 76635cf5d..bd534e917 100644
--- a/portlist.cc
+++ b/portlist.cc
@@ -897,17 +897,23 @@ bool PortList::isTCPwrapped(u16 portno) const {
   const Port *port = lookupPort(portno, IPPROTO_TCP);
   if (port == NULL) {
     if (o.debugging > 1) {
-      log_write(LOG_STDOUT, "PortList::isTCPwrapped(%d) requested but port not in list", portno);
+      log_write(LOG_STDOUT, "PortList::isTCPwrapped(%d) requested but port not in list\n", portno);
     }
     return false;
   } else if (!o.servicescan) {
     if (o.debugging > 1) {
-      log_write(LOG_STDOUT, "PortList::isTCPwrapped(%d) requested but service scan was never asked to be done", portno);
+      log_write(LOG_STDOUT, "PortList::isTCPwrapped(%d) requested but service scan was never asked to be done\n", portno);
     }
     return false;
   } else if (port->service == NULL) {
     if (o.debugging > 1) {
-      log_write(LOG_STDOUT, "PortList::isTCPwrapped(%d) requested but port has not been service scanned yet", portno);
+      log_write(LOG_STDOUT, "PortList::isTCPwrapped(%d) requested but port has not been service scanned yet\n", portno);
+    }
+    return false;
+  } else if (port->service->name == NULL) {
+    // no service match and port not listed in services file
+    if (o.debugging > 1) {
+      log_write(LOG_STDOUT, "PortList::isTCPwrapped(%d) requested but service has no name\n", portno);
     }
     return false;
   } else {