diff --git a/src/internet-stack/nsc-tcp-l4-protocol.cc b/src/internet-stack/nsc-tcp-l4-protocol.cc
index 63d08190e..77fdc1597 100644
--- a/src/internet-stack/nsc-tcp-l4-protocol.cc
+++ b/src/internet-stack/nsc-tcp-l4-protocol.cc
@@ -39,8 +39,8 @@
 #include <dlfcn.h>
 #include <iomanip>
 
-#include <netinet/ip.h>
-#include <netinet/tcp.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
 
 NS_LOG_COMPONENT_DEFINE ("NscTcpL4Protocol");
 
@@ -313,27 +313,31 @@ void NscTcpL4Protocol::SoftInterrupt (void)
 void NscTcpL4Protocol::send_callback(const void* data, int datalen)
 {
   Ptr<Packet> p;
+  uint32_t ipv4Saddr, ipv4Daddr;
 
-  NS_ASSERT(datalen > (int)sizeof(struct iphdr));
+  NS_ASSERT(datalen > 20);
 
-  const uint8_t *rawdata = reinterpret_cast<const uint8_t *>(data);
-  rawdata += sizeof(struct iphdr);
-
-  const struct iphdr *ipHdr = reinterpret_cast<const struct iphdr *>(data);
 
   // create packet, without IP header. The TCP header is not touched.
   // Not using the IP header makes integration easier, but it destroys
   // eg. ECN.
-  p = Create<Packet> (rawdata, datalen - sizeof(struct iphdr));
+  const uint8_t *rawdata = reinterpret_cast<const uint8_t *>(data);
+  rawdata += 20; // skip IP header. IP options aren't supported at this time.
+  datalen -= 20;
+  p = Create<Packet> (rawdata, datalen);
 
-  Ipv4Address saddr(ntohl(ipHdr->saddr));
-  Ipv4Address daddr(ntohl(ipHdr->daddr));
+  // we need the real source/destination ipv4 addresses for Send ().
+  const uint32_t *ipheader = reinterpret_cast<const uint32_t *>(data);
+  ipv4Saddr = *(ipheader+3);
+  ipv4Daddr = *(ipheader+4);
+
+  Ipv4Address saddr(ntohl(ipv4Saddr));
+  Ipv4Address daddr(ntohl(ipv4Daddr));
 
   Ptr<Ipv4L3Protocol> ipv4 = m_node->GetObject<Ipv4L3Protocol> ();
-  if (ipv4 != 0)
-    {
-      ipv4->Send (p, saddr, daddr, PROT_NUMBER);
-    }
+  NS_ASSERT_MSG (ipv4, "nsc callback invoked, but node has no ipv4 object");
+
+  ipv4->Send (p, saddr, daddr, PROT_NUMBER);
   m_nscStack->if_send_finish(0);
 }
 
diff --git a/src/internet-stack/nsc-tcp-socket-impl.cc b/src/internet-stack/nsc-tcp-socket-impl.cc
index 79ac08b1d..3023f49d2 100644
--- a/src/internet-stack/nsc-tcp-socket-impl.cc
+++ b/src/internet-stack/nsc-tcp-socket-impl.cc
@@ -33,11 +33,9 @@
 
 #include <algorithm>
 
-#include <sys/socket.h>
-#include <netinet/in.h>
+// for ntohs().
 #include <arpa/inet.h>
-#include <netinet/ip.h>
-#include <netinet/tcp.h>
+#include <netinet/in.h>
 
 #include "sim_interface.h"
 #include "sim_errno.h"
@@ -307,13 +305,11 @@ NscTcpSocketImpl::Connect (const Address & address)
   m_remoteAddress = transport.GetIpv4 ();
   m_remotePort = transport.GetPort ();
 
-  struct in_addr remoteAddr;
-  uint32_t addr32;
+  std::ostringstream ss;
+  m_remoteAddress.Print(ss);
+  std::string ipstring = ss.str ();
 
-  m_remoteAddress.Serialize((uint8_t*)&addr32);
-  remoteAddr.s_addr = addr32;
-
-  m_nscTcpSocket->connect(inet_ntoa(remoteAddr), m_remotePort);
+  m_nscTcpSocket->connect(ipstring.c_str (), m_remotePort);
   m_state = SYN_SENT;
   return 0;
 }