diff --git a/Makefile b/Makefile
index f65e7d8..847118e 100644
--- a/Makefile
+++ b/Makefile
@@ -17,6 +17,7 @@ CFLAGS += -I/usr/include/pcap
 # directories:
 #LDFLAGS += -L/usr/local/lib
 # LDFLAGS += -pg -a
+LDFLAGS += -pthread
 
 # PREFIX specifies the base directory for the installation.
 PREFIX = /usr/local
@@ -30,10 +31,10 @@ MANDIR = man
 #MANDIR = share/man     # FHS-ish
 
 # You shouldn't need to change anything below this point.
-VERSION = 0.9pre3
+VERSION = 0.9pre4
 CFLAGS  += -g -Wall "-DIFTOP_VERSION=\"$(VERSION)\""
 LDFLAGS += -g 
-LDLIBS += -lpcap -lpthread -lcurses -lm
+LDLIBS += -lpcap -lcurses -lm
 
 SRCS = iftop.c addr_hash.c hash.c ns_hash.c resolver.c ui.c util.c sorted_list.c\
        options.c serv_hash.c threadprof.c
diff --git a/iftop.c b/iftop.c
index 03e857d..b2c45b6 100644
--- a/iftop.c
+++ b/iftop.c
@@ -134,7 +134,7 @@ void assign_addr_pair(addr_pair* ap, struct ip* iptr, int flip) {
   unsigned short int dst_port = 0;
 
   /* Does this protocol use ports? */
-  if(iptr->ip_p == IPPROTO_TCP || IP_HL(iptr) == IPPROTO_UDP) {
+  if(iptr->ip_p == IPPROTO_TCP || iptr->ip_p == IPPROTO_UDP) {
     /* We take a slight liberty here by treating UDP the same as TCP */
 
     /* Find the TCP/UDP header */
diff --git a/iftop.h b/iftop.h
index 0d01fee..cad1d95 100644
--- a/iftop.h
+++ b/iftop.h
@@ -35,7 +35,7 @@ void options_read(int argc, char **argv);
 
 
 /* Make use of SIOCGIFHWADDR work on FreeBSD */
-#ifdef __BSD__
+#ifndef SIOCGIFHWADDR
 #define SIOCGIFHWADDR SIOCGIFADDR
 #define ifr_hwaddr ifr_addr
 #endif
diff --git a/ns_hash.c b/ns_hash.c
index 74e1744..3a1d463 100644
--- a/ns_hash.c
+++ b/ns_hash.c
@@ -2,7 +2,9 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <sys/types.h>
 #include <sys/socket.h>
+#include <netinet/in_systm.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include "ns_hash.h"
diff --git a/ns_hash.h b/ns_hash.h
index be644cd..78814be 100644
--- a/ns_hash.h
+++ b/ns_hash.h
@@ -8,6 +8,7 @@
 #ifndef __NS_HASH_H_ /* include guard */
 #define __NS_HASH_H_
 
+#include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
diff --git a/resolver.c b/resolver.c
index e98cbf0..8602421 100644
--- a/resolver.c
+++ b/resolver.c
@@ -3,8 +3,9 @@
  *
  */
 
-#include <netinet/in.h>
+#include <sys/types.h>
 #include <sys/socket.h>
+#include <netinet/in.h>
 #include <arpa/inet.h>
 #include <pthread.h>
 #include <stdio.h>
diff --git a/resolver.h b/resolver.h
index efad57c..836fe25 100644
--- a/resolver.h
+++ b/resolver.h
@@ -6,8 +6,12 @@
 #ifndef __RESOLVER_H_ /* include guard */
 #define __RESOLVER_H_
 
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in_systm.h>
 #include <netinet/in.h>
 
+
 void resolver_initialise();
 
 void resolve(struct in_addr* addr, char* result, int buflen);
diff --git a/serv_hash.h b/serv_hash.h
index 6241134..2d9ecde 100644
--- a/serv_hash.h
+++ b/serv_hash.h
@@ -6,6 +6,7 @@
 #ifndef __SERV_HASH_H_ /* include guard */
 #define __SERV_HASH_H_
 
+#include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>