diff --git a/Makefile b/Makefile
index ab251f4..6c99b3f 100644
--- a/Makefile
+++ b/Makefile
@@ -1,36 +1,77 @@
 PROGNAME=dump1090
 
-# Try to autodetect available libraries if no explicit setting was used
-
-ifndef RTLSDR
-  ifdef RTLSDR_PREFIX
-    RTLSDR := yes
-  else
-    RTLSDR := $(shell pkg-config --exists librtlsdr && echo "yes" || echo "no")
-  endif
-endif
-
-ifndef BLADERF
-  BLADERF := $(shell pkg-config --exists libbladeRF && echo "yes" || echo "no")
-endif
-
-ifndef HACKRF
-  HACKRF := $(shell pkg-config --exists libhackrf && echo "yes" || echo "no")
-endif
-
-ifndef LIMESDR
-  LIMESDR := $(shell pkg-config --exists LimeSuite && echo "yes" || echo "no")
-endif
-
 DUMP1090_VERSION ?= unknown
 
 CPPFLAGS += -DMODES_DUMP1090_VERSION=\"$(DUMP1090_VERSION)\" -DMODES_DUMP1090_VARIANT=\"dump1090-fa\"
 
 DIALECT = -std=c11
 CFLAGS += $(DIALECT) -O3 -g -Wall -Wmissing-declarations -Werror -W -D_DEFAULT_SOURCE -fno-common
-LIBS = -lpthread -lm -lrt
+LIBS = -lpthread -lm
 SDR_OBJ = sdr.o fifo.o sdr_ifile.o
 
+# Try to autodetect available libraries via pkg-config if no explicit setting was used
+PKGCONFIG=$(shell pkg-config --version >/dev/null 2>&1 && echo "yes" || echo "no")
+ifeq ($(PKGCONFIG), yes)
+  ifndef RTLSDR
+    ifdef RTLSDR_PREFIX
+      RTLSDR := yes
+    else
+      RTLSDR := $(shell pkg-config --exists librtlsdr && echo "yes" || echo "no")
+    endif
+  endif
+
+  ifndef BLADERF
+    BLADERF := $(shell pkg-config --exists libbladeRF && echo "yes" || echo "no")
+  endif
+
+  ifndef HACKRF
+    HACKRF := $(shell pkg-config --exists libhackrf && echo "yes" || echo "no")
+  endif
+
+  ifndef LIMESDR
+    LIMESDR := $(shell pkg-config --exists LimeSuite && echo "yes" || echo "no")
+  endif
+else
+  # pkg-config not available. Only use explicitly enabled libraries.
+  RTLSDR ?= no
+  BLADERF ?= no
+  HACKRF ?= no
+  LIMESDR ?= no
+endif
+
+UNAME := $(shell uname)
+
+ifeq ($(UNAME), Linux)
+  CFLAGS += -D_DEFAULT_SOURCE
+  LIBS += -lrt
+  LIBS_USB += -lusb-1.0
+endif
+
+ifeq ($(UNAME), Darwin)
+  ifneq ($(shell sw_vers -productVersion | egrep '^10\.([0-9]|1[01])\.'),) # Mac OS X ver <= 10.11
+    CFLAGS += -DMISSING_GETTIME
+    COMPAT += compat/clock_gettime/clock_gettime.o
+  endif
+  CFLAGS += -DMISSING_NANOSLEEP
+  COMPAT += compat/clock_nanosleep/clock_nanosleep.o
+  LIBS_USB += -lusb-1.0
+endif
+
+ifeq ($(UNAME), OpenBSD)
+  CFLAGS += -DMISSING_NANOSLEEP
+  COMPAT += compat/clock_nanosleep/clock_nanosleep.o
+  LIBS_USB += -lusb-1.0
+endif
+
+ifeq ($(UNAME), FreeBSD)
+  CFLAGS += -D_DEFAULT_SOURCE
+  LIBS += -lrt
+  LIBS_USB += -lusb
+endif
+
+RTLSDR ?= yes
+BLADERF ?= yes
+
 ifeq ($(RTLSDR), yes)
   SDR_OBJ += sdr_rtlsdr.o
   CPPFLAGS += -DENABLE_RTLSDR
@@ -38,13 +79,19 @@ ifeq ($(RTLSDR), yes)
   ifdef RTLSDR_PREFIX
     CPPFLAGS += -I$(RTLSDR_PREFIX)/include
     ifeq ($(STATIC), yes)
-      LIBS_SDR += -L$(RTLSDR_PREFIX)/lib -Wl,-Bstatic -lrtlsdr -Wl,-Bdynamic -lusb-1.0
+      LIBS_SDR += -L$(RTLSDR_PREFIX)/lib -Wl,-Bstatic -lrtlsdr -Wl,-Bdynamic $(LIBS_USB)
     else
-      LIBS_SDR += -L$(RTLSDR_PREFIX)/lib -lrtlsdr -lusb-1.0
+      LIBS_SDR += -L$(RTLSDR_PREFIX)/lib -lrtlsdr $(LIBS_USB)
     endif
   else
-    CFLAGS += $(shell pkg-config --cflags librtlsdr)
     # some packaged .pc files are massively broken, try to handle it
+
+    # FreeBSD's librtlsdr.pc includes -std=gnu89 in cflags
+    RTLSDR_CFLAGS := $(shell pkg-config --cflags librtlsdr)
+    CFLAGS += $(filter-out -std=%,$(RTLSDR_CFLAGS))
+
+    # some linux librtlsdr packages return a bare -L with no path in --libs
+    # which horribly confuses things because it eats the next option on the command line
     RTLSDR_LFLAGS := $(shell pkg-config --libs-only-L librtlsdr)
     ifeq ($(RTLSDR_LFLAGS),-L)
       LIBS_SDR += $(shell pkg-config --libs-only-l --libs-only-other librtlsdr)
diff --git a/README.md b/README.md
index 14e013a..2d6cdb2 100644
--- a/README.md
+++ b/README.md
@@ -90,3 +90,15 @@ libhackrf.
 
 ``make LIMESDR=no`` will disable LimeSDR support and remove the dependency on
 libLimeSuite.
+
+## Building on OSX
+
+Minimal testing, YMMV.
+
+```
+$ brew install librtlsdr
+$ brew install libbladerf
+$ brew install pkg-config
+$ make
+```
+
diff --git a/compat/clock_gettime/clock_gettime.c b/compat/clock_gettime/clock_gettime.c
index 372ff2e..cd2f824 100644
--- a/compat/clock_gettime/clock_gettime.c
+++ b/compat/clock_gettime/clock_gettime.c
@@ -58,8 +58,8 @@
  *
  */
 
-
-#include "clock_gettime.h"
+#include "../compat.h"
+#include <mach/mach_time.h>
 #include <mach/clock.h>             // for clock_get_time
 #include <mach/clock_types.h>       // for mach_timespec_t, CALENDAR_CLOCK, etc
 #include <mach/kern_return.h>       // for KERN_SUCCESS, kern_return_t
@@ -70,6 +70,8 @@
 #include <errno.h>                  // for EINVAL, errno
 #include <unistd.h>                 // for getpid
 
+static mach_timebase_info_data_t __clock_gettime_inf;
+
 int clock_gettime(clockid_t clk_id, struct timespec *tp)
 {
     kern_return_t   ret;
diff --git a/compat/clock_gettime/clock_gettime.h b/compat/clock_gettime/clock_gettime.h
index 83fdac7..a7dc7ae 100644
--- a/compat/clock_gettime/clock_gettime.h
+++ b/compat/clock_gettime/clock_gettime.h
@@ -1,27 +1,6 @@
 #ifndef CLOCK_GETTIME_H
 #define CLOCK_GETTIME_H
 
-#include <mach/mach_time.h> // Apple-only, but this isn't inclued on other BSDs
-
-#ifdef _CLOCKID_T_DEFINED_
-#define CLOCKID_T
-#endif
-
-#ifndef CLOCKID_T
-#define CLOCKID_T
-typedef enum
-{
-    CLOCK_REALTIME,
-    CLOCK_MONOTONIC,
-    CLOCK_PROCESS_CPUTIME_ID,
-    CLOCK_THREAD_CPUTIME_ID
-} clockid_t;
-#endif // ifndef CLOCKID_T
-
-struct timespec;
-
-static mach_timebase_info_data_t __clock_gettime_inf;
-
 int clock_gettime(clockid_t clk_id, struct timespec *tp);
 
 #endif // CLOCK_GETTIME_H
diff --git a/compat/clock_nanosleep/clock_nanosleep.c b/compat/clock_nanosleep/clock_nanosleep.c
index f6e3d84..0eeb359 100644
--- a/compat/clock_nanosleep/clock_nanosleep.c
+++ b/compat/clock_nanosleep/clock_nanosleep.c
@@ -22,10 +22,7 @@
 #include <errno.h>                           // for errno, EINVAL
 #include <time.h>                            // for nanosleep, NULL
 
-#include "clock_nanosleep.h"
-#ifdef MISSING_GETTIME
-#include "../clock_gettime/clock_gettime.h"  // for clock_gettime
-#endif
+#include "../compat.h"
 
 int clock_nanosleep(clockid_t id, int flags, const struct timespec *ts,
                     struct timespec *ots) {
diff --git a/compat/clock_nanosleep/clock_nanosleep.h b/compat/clock_nanosleep/clock_nanosleep.h
index 9a8da5d..5e1f0c3 100644
--- a/compat/clock_nanosleep/clock_nanosleep.h
+++ b/compat/clock_nanosleep/clock_nanosleep.h
@@ -1,28 +1,6 @@
 #ifndef CLOCK_NANOSLEEP_H
 #define CLOCK_NANOSLEEP_H
 
-#ifdef _CLOCKID_T_DEFINED_
-#define CLOCKID_T
-#endif
-
-#ifndef CLOCKID_T
-#define CLOCKID_T
-typedef enum
-{
-    CLOCK_REALTIME,
-    CLOCK_MONOTONIC,
-    CLOCK_PROCESS_CPUTIME_ID,
-    CLOCK_THREAD_CPUTIME_ID
-} clockid_t;
-#endif // ifndef CLOCKID_T
-
-
-#ifndef TIMER_ABSTIME
-#define TIMER_ABSTIME 1
-#endif // TIMER_ABSTIME
-
-struct timespec;
-
 int clock_nanosleep (clockid_t id, int flags, const struct timespec *ts,
                      struct timespec *ots);
 
diff --git a/compat/compat.h b/compat/compat.h
index 5905e10..f94015f 100644
--- a/compat/compat.h
+++ b/compat/compat.h
@@ -17,6 +17,10 @@
 # include <machine/endian.h>
 # define le16toh(x) OSSwapLittleToHostInt16(x)
 # define le32toh(x) OSSwapLittleToHostInt32(x)
+# define le64toh(x) OSSwapLittleToHostInt64(x)
+
+#elif defined(__FreeBSD__)
+#include <sys/endian.h>
 
 #else // other platforms
 
@@ -24,6 +28,30 @@
 
 #endif
 
+/* clock_* and time-related types */
+
+#include <time.h>
+
+#if defined(CLOCK_REALTIME)
+#  define HAVE_CLOCKID_T
+#endif
+
+#ifndef HAVE_CLOCKID_T
+typedef enum
+{
+    CLOCK_REALTIME,
+    CLOCK_MONOTONIC,
+    CLOCK_PROCESS_CPUTIME_ID,
+    CLOCK_THREAD_CPUTIME_ID
+} clockid_t;
+#endif // !HAVE_CLOCKID_T
+
+#ifndef TIMER_ABSTIME
+#define TIMER_ABSTIME 1
+#endif // !TIMER_ABSTIME
+
+struct timespec;
+
 #ifdef MISSING_NANOSLEEP
 #include "clock_nanosleep/clock_nanosleep.h"
 #endif