diff --git a/client.c b/client.c
index 502fa7dc..90dd9f1d 100644
--- a/client.c
+++ b/client.c
@@ -52,8 +52,8 @@ int packetSendFollowup(struct in_addr destination,
       fprintf(stderr,"Could not create UDP socket.\n");
       exit(-3);
     }
-    int TRUE=1;
-    setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &TRUE, sizeof(TRUE));
+    r=1;
+    setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &r, sizeof(r));
   }
   
   r=sendto(sock,packet,packet_len,0,(struct sockaddr *)&peer_addr,sizeof(peer_addr));
@@ -86,8 +86,8 @@ int packetSendRequest(int method,unsigned char *packet,int packet_len,int batchP
       fprintf(stderr,"Could not create UDP socket.\n");
       exit(-3);
     }
-    int TRUE=1;
-    setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &TRUE, sizeof(TRUE));
+    i=1;
+    setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &i, sizeof(i));
   }
   
   /* Deal with special case */
diff --git a/commandline.c b/commandline.c
index 6500c449..eb0a860f 100644
--- a/commandline.c
+++ b/commandline.c
@@ -17,7 +17,6 @@ along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
 
-#define _GNU_SOURCE // For asprintf()
 #include <sys/time.h>
 #include <sys/wait.h>
 #include <math.h>
diff --git a/configure.in b/configure.in
index f3e3916f..5dd3328d 100644
--- a/configure.in
+++ b/configure.in
@@ -1,6 +1,8 @@
 dnl Process this file with autoconf to produce a configure script.
 AC_INIT(dna.c)
 
+CPPFLAGS=-D_GNU_SOURCE
+
 dnl Set $host_os, which is needed by javac detection.
 AC_CANONICAL_SYSTEM
 
@@ -37,11 +39,16 @@ dnl Math library functions for spandsp
 AC_CHECK_HEADERS([math.h], [INSERT_MATH_HEADER="#include <math.h>"])
 AC_CHECK_HEADERS([float.h])
 
-dnl Math library functions for spandsp
+dnl Check for Linux version of struct ucred
 AC_CHECK_MEMBER(struct ucred.uid,
-    [AC_DEFINE([HAVE_STRUCT_UCRED], 1)],,
+    [AC_DEFINE([HAVE_LINUX_STRUCT_UCRED], 1)],,
     [#include <sys/socket.h>])
 
+dnl Check for BSD version of struct ucred
+AC_CHECK_MEMBER(struct xucred.cr_uid,
+    [AC_DEFINE([HAVE_BSD_STRUCT_UCRED], 1)],,
+    [#include <sys/ucred.h>])
+
 dnl Check for a working Java compiler, keep going if unsuccessful.
 dnl *** Kludge: override AC_MSG_ERROR because AC_PROG_JAVAC does not have
 dnl *** [if-found] and [if-not-found] action parameters.
@@ -75,9 +82,11 @@ AC_CHECK_HEADERS(
     sys/socket.h \
     sys/mman.h \
     sys/time.h \
+    sys/ucred.h \
     poll.h \
     netdb.h \
     linux/if.h \
+    linux/ioctl.h \
     linux/netlink.h \
     linux/rtnetlink.h \
     net/if.h \
diff --git a/monitor.c b/monitor.c
index cda8fc4a..617e6368 100644
--- a/monitor.c
+++ b/monitor.c
@@ -27,13 +27,9 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #include "rhizome.h"
 #include <sys/stat.h>
 
-#ifndef HAVE_STRUCT_UCRED
-struct ucred {
-  pid_t pid;
-  uid_t uid;
-  gid_t gid;
-};
-#endif // HAVE_STRUCT_UCRED
+#if defined(LOCAL_PEERCRED) && !defined(SO_PEERCRED)
+#define SO_PEERCRED LOCAL_PEERCRED
+#endif
 
 /* really shouldn't need more than 2:
    1 for rhizome
@@ -202,7 +198,14 @@ int monitor_poll()
     WHYF("ignored_length=%d",ignored_length);
     int res = fcntl(s,F_SETFL, O_NONBLOCK);
     if (res) { close(s); continue; }
+#if defined(HAVE_LINUX_STRUCT_UCRED)
     struct ucred ucred;
+#elif defined(HAVE_BSD_STRUCT_UCRED)
+    struct xucred ucred;
+#else
+#error "Unknown ucred struct"
+#endif
+    uid_t otheruid;
     socklen_t len=sizeof(ucred);
     res = getsockopt(s,SOL_SOCKET,SO_PEERCRED,&ucred,&len);
     if (len>sizeof(ucred)) {
@@ -211,9 +214,14 @@ int monitor_poll()
     if (res) { 
       WHY("Failed to read credentials of monitor.socket client");
       close(s); continue; }
-    if (ucred.uid&&(ucred.uid!=getuid())) {
+#if defined(HAVE_LINUX_STRUCT_UCRED)
+    otheruid = ucred.uid;
+#elif defined(HAVE_BSD_STRUCT_UCRED)
+    otheruid = ucred.cr_uid;
+#endif
+    if (otheruid&&(otheruid!=getuid())) {
       WHYF("monitor.socket client has wrong uid (%d versus %d)",
-	   ucred.uid,getuid());
+	   otheruid,getuid());
       write(s,"\nCLOSE:Incorrect UID\n",strlen("\nCLOSE:Incorrect UID\n"));
       close(s); continue;
     }
diff --git a/pa_phone.c b/pa_phone.c
index 8508fb8e..0c840988 100644
--- a/pa_phone.c
+++ b/pa_phone.c
@@ -11,8 +11,6 @@
 #define NUM_BUFS	(8)
 #define ECHO_LEN	(128)
 #define ADAPT_MODE	(ECHO_CAN_USE_ADAPTION | ECHO_CAN_USE_NLP | ECHO_CAN_USE_CNG)
-#define MIN(x, y)	((x) > (y) ? y : x)
-#define MAX(x, y)	((x) < (y) ? y : x)
 
 #define CODEC2_BYTES_PER_FRAME ((CODEC2_BITS_PER_FRAME + 7) / 8)
 
diff --git a/serval.h b/serval.h
index 8306f4dd..aec16d87 100755
--- a/serval.h
+++ b/serval.h
@@ -59,6 +59,10 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #ifdef HAVE_IFADDRS_H
 #include <ifaddrs.h>
 #endif
+
+#ifdef HAVE_SYS_UCRED_H
+#include <sys/ucred.h>
+#endif
 #endif
 
 #if !defined(FORASTERISK) && !defined(s_addr)
diff --git a/server.c b/server.c
index 54c98294..2461ab77 100644
--- a/server.c
+++ b/server.c
@@ -791,11 +791,11 @@ int createServerSocket()
   fcntl(sock, F_SETFL,
 	fcntl(sock, F_GETFL, NULL)|O_CLOEXEC);
 
-  int TRUE=1;
-  setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &TRUE, sizeof(TRUE));
+  int i=1;
+  setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &i, sizeof(i));
 
   errno=0;
-  if(setsockopt(sock, IPPROTO_IP, IP_RECVTTL, &TRUE,sizeof(TRUE))<0)
+  if(setsockopt(sock, IPPROTO_IP, IP_RECVTTL, &i,sizeof(i))<0)
     WHY_perror("setsockopt(IP_RECVTTL)");  
 
   bind_addr.sin_family = AF_INET;