diff --git a/configure.in b/configure.in
index 62aaf72..639e1c4 100644
--- a/configure.in
+++ b/configure.in
@@ -1749,6 +1749,7 @@ AC_CHECK_FUNCS(_setjmpex)		# used for AC_ARG_WITH(setjmp-type)
 AC_CHECK_FUNCS(chroot)
 AC_CHECK_FUNCS(chsize)
 AC_CHECK_FUNCS(clock_gettime)
+AC_CHECK_FUNCS(mach_absolute_time)
 AC_CHECK_FUNCS(cosh)
 AC_CHECK_FUNCS(daemon)
 AC_CHECK_FUNCS(dl_iterate_phdr)
diff --git a/process.c b/process.c
index b3a9282..36d8a75 100644
--- a/process.c
+++ b/process.c
@@ -74,6 +74,9 @@
 #ifdef HAVE_SYS_TIMES_H
 #include <sys/times.h>
 #endif
+#ifdef HAVE_MACH_ABSOLUTE_TIME
+#include <mach/mach_time.h>
+#endif
 
 #ifdef HAVE_PWD_H
 #include <pwd.h>
@@ -6637,6 +6640,44 @@ rb_proc_times(VALUE obj)
 #define rb_proc_times rb_f_notimplement
 #endif
 
+#ifdef HAVE_MACH_ABSOLUTE_TIME
+
+#if SIZEOF_LONG == 8
+# define UINT64toNUM(x) ULONG2NUM(x)
+# define NUMtoUINT64(x) NUM2ULONG(x)
+#elif defined(HAVE_LONG_LONG) && SIZEOF_LONG_LONG == 8
+# define UINT64toNUM(x) ULL2NUM(x)
+# define NUMtoUINT64(x) NUM2ULL(x)
+#endif
+
+static mach_timebase_info_data_t sTimebaseInfo;
+
+/*
+ *  call-seq:
+ *     Process.mach_absolute_time()   -> number
+ *
+ *  Returns an absolute number representing the time and is CPU dependent.
+ */
+static VALUE
+rb_mach_absolute_time(VALUE mod)
+{
+    return UINT64toNUM(mach_absolute_time());
+}
+
+static VALUE
+rb_absolute_to_ns(VALUE mod, VALUE _abs)
+{
+    uint64_t abs;
+    uint64_t ns;
+
+    abs = NUMtoUINT64(_abs);
+    ns = abs * sTimebaseInfo.numer / sTimebaseInfo.denom;
+
+    return UINT64toNUM(ns);
+}
+
+#endif
+
 /*
  *  call-seq:
  *     Process.clock_gettime(clk_id [, unit])   -> number
@@ -7107,6 +7148,12 @@ Init_process(void)
 #endif
     rb_define_module_function(rb_mProcess, "clock_gettime", rb_clock_gettime, -1);
 
+#ifdef HAVE_MACH_ABSOLUTE_TIME
+    rb_define_module_function(rb_mProcess, "mach_absolute_time", rb_mach_absolute_time, 0);
+    rb_define_module_function(rb_mProcess, "absolute_to_ns", rb_absolute_to_ns, 1);
+    mach_timebase_info(&sTimebaseInfo);
+#endif
+
 #if defined(HAVE_TIMES) || defined(_WIN32)
     rb_cProcessTms = rb_struct_define("Tms", "utime", "stime", "cutime", "cstime", NULL);
 #endif
diff --git a/test/ruby/test_process.rb b/test/ruby/test_process.rb
index 2e7f3a4..ef766d8 100644
--- a/test/ruby/test_process.rb
+++ b/test/ruby/test_process.rb
@@ -1669,4 +1669,15 @@ EOS
     assert_raise(Errno::EINVAL) { Process.clock_gettime(:foo) }
   end
 
+  def test_mach_absolute_time
+    x = 3.times.map { Process.mach_absolute_time }
+    x.each_cons(2) { |l,r| assert_operator(l, :<=, r) }
+  end if Process.respond_to?(:mach_absolute_time)
+
+  def test_absolute_to_ns
+    x = 3.times.map { Process.mach_absolute_time }
+    x.each_cons(2) { |l,r|
+      assert_operator(Process.absolute_to_ns(r - l), :>, 0)
+    }
+  end if Process.respond_to?(:mach_absolute_time)
 end