diff --git a/common.c b/common.c
index bbe36780..d5ce6a5a 100644
--- a/common.c
+++ b/common.c
@@ -35,6 +35,7 @@
 #include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <inttypes.h> // PRIdPTR
 #include <libgen.h>
 #include <memory.h>
 #include <poll.h>
@@ -54,7 +55,7 @@
 #include <netpacket/packet.h>
 #endif
 
-#ifdef COMPILE_FOR_FREEBSD
+#ifdef COMPILE_FOR_BSD
 #include <net/if_dl.h>
 #include <net/if_types.h>
 #include <netinet/in.h>
diff --git a/configure.ac b/configure.ac
index 7f31e167..0af2d024 100644
--- a/configure.ac
+++ b/configure.ac
@@ -17,15 +17,18 @@ AM_CONDITIONAL([USE_GIT_VERSION], [test -n "$GIT" && test -e ".git/index" ])
 # Derived from the Avahi configure.ac file
 # Specifying the OS type, defaulting to linux.
 #
-AC_ARG_WITH(os, AS_HELP_STRING([--with-os=OSType],[Specify the distribution to target: One of linux freebsd or darwin]))
+AC_ARG_WITH(os, AS_HELP_STRING([--with-os=OSType],[Specify the distribution to target: One of linux, freebsd, openbsd or darwin]))
 if test "z$with_os" = "z"; then
   with_os="linux"
 fi
 with_os=`echo ${with_os} | tr '[[:upper:]]' '[[:lower:]]' `
-
-if test "x${with_os}" != xlinux && "x${with_os}" != xfreebsd && "x${with_os}" != xdarwin ; then
-	AC_MSG_ERROR(--with-os=<arg> argument must linux freebsd openbsd or darwin)
-fi
+case "x${with_os}" in
+xlinux|xfreebsd|xopenbsd|xdarwin)
+  ;;
+*)
+  AC_MSG_ERROR([--with-os=<arg> argument must be one of linux, freebsd, openbsd or darwin])
+  ;;
+esac
 
 # Checks for programs.
 AC_PROG_CC
diff --git a/shairport.c b/shairport.c
index e2fd0b5e..f799f8a7 100644
--- a/shairport.c
+++ b/shairport.c
@@ -120,6 +120,8 @@ int this_is_the_daemon_process = 0;
 #define UUID_STR_LEN 36
 #endif
 
+#define strnull(s) ((s) ? (s) : "(null)")
+
 pthread_t rtsp_listener_thread;
 
 int killOption = 0;
@@ -1986,15 +1988,15 @@ int main(int argc, char **argv) {
   debug(1, "udp port range is %d.", config.udp_port_range);
   debug(1, "player name is \"%s\".", config.service_name);
   debug(1, "backend is \"%s\".", config.output_name);
-  debug(1, "run_this_before_play_begins action is \"%s\".", config.cmd_start);
-  debug(1, "run_this_after_play_ends action is \"%s\".", config.cmd_stop);
+  debug(1, "run_this_before_play_begins action is \"%s\".", strnull(config.cmd_start));
+  debug(1, "run_this_after_play_ends action is \"%s\".", strnull(config.cmd_stop));
   debug(1, "wait-cmd status is %d.", config.cmd_blocking);
   debug(1, "run_this_before_play_begins may return output is %d.", config.cmd_start_returns_output);
-  debug(1, "run_this_if_an_unfixable_error_is_detected action is \"%s\".", config.cmd_unfixable);
-  debug(1, "run_this_before_entering_active_state action is  \"%s\".", config.cmd_active_start);
-  debug(1, "run_this_after_exiting_active_state action is  \"%s\".", config.cmd_active_stop);
+  debug(1, "run_this_if_an_unfixable_error_is_detected action is \"%s\".", strnull(config.cmd_unfixable));
+  debug(1, "run_this_before_entering_active_state action is  \"%s\".", strnull(config.cmd_active_start));
+  debug(1, "run_this_after_exiting_active_state action is  \"%s\".", strnull(config.cmd_active_stop));
   debug(1, "active_state_timeout is  %f seconds.", config.active_state_timeout);
-  debug(1, "mdns backend \"%s\".", config.mdns_name);
+  debug(1, "mdns backend \"%s\".", strnull(config.mdns_name));
   debug(2, "userSuppliedLatency is %d.", config.userSuppliedLatency);
   debug(1, "interpolation setting is \"%s\".",
         config.packet_stuffing == ST_basic  ? "basic"
@@ -2005,7 +2007,7 @@ int main(int argc, char **argv) {
   debug(1, "allow a session to be interrupted: %d.", config.allow_session_interruption);
   debug(1, "busy timeout time is %d.", config.timeout);
   debug(1, "drift tolerance is %f seconds.", config.tolerance);
-  debug(1, "password is \"%s\".", config.password);
+  debug(1, "password is \"%s\".", strnull(config.password));
   debug(1, "ignore_volume_control is %d.", config.ignore_volume_control);
   if (config.volume_max_db_set)
     debug(1, "volume_max_db is %d.", config.volume_max_db);