diff --git a/include/common.h b/include/common.h
index c84363a4f..de176b614 100644
--- a/include/common.h
+++ b/include/common.h
@@ -45,6 +45,7 @@
 #include <termios.h>
 #include <sys/ioctl.h>
 #include <mach-o/dyld.h>
+#include <mach/mach.h>
 #endif
 
 typedef void *OCL_LIB;
diff --git a/include/shared.h b/include/shared.h
index 9bf5cc106..891f5164c 100644
--- a/include/shared.h
+++ b/include/shared.h
@@ -43,7 +43,18 @@
 #define hc_thread_mutex_unlock(m)   pthread_mutex_unlock   (&m)
 #define hc_thread_mutex_init(m)     pthread_mutex_init     (&m, NULL)
 #define hc_thread_mutex_delete(m)   pthread_mutex_destroy  (&m)
+#endif
 
+#ifdef OSX
+typedef struct cpu_set
+{
+  uint32_t count;
+
+} cpu_set_t;
+
+static inline void CPU_ZERO  (cpu_set_t *cs)          { cs->count = 0; }
+static inline void CPU_SET   (int num, cpu_set_t *cs) { cs->count |= (1 << num); }
+static inline int  CPU_ISSET (int num, cpu_set_t *cs) { return (cs->count & (1 << num)); }
 #endif
 
 /**
diff --git a/src/oclHashcat.c b/src/oclHashcat.c
index e4eaca546..36583fc54 100644
--- a/src/oclHashcat.c
+++ b/src/oclHashcat.c
@@ -390,11 +390,7 @@ const char *USAGE_BIG[] =
   "  -c,  --segment-size=NUM            Size in MB to cache from the wordfile",
   "       --bitmap-min=NUM              Minimum number of bits allowed for bitmaps",
   "       --bitmap-max=NUM              Maximum number of bits allowed for bitmaps",
-  #ifndef OSX
   "       --cpu-affinity=STR            Locks to CPU devices, separate with comma",
-  #else
-  "       --cpu-affinity=STR            Locks to CPU devices, separate with comma (disabled on OSX)",
-  #endif
   "       --opencl-platforms=STR        OpenCL platforms to use, separate with comma",
   "  -d,  --opencl-devices=STR          OpenCL devices to use, separate with comma",
   "       --opencl-device-types=STR     OpenCL device-types to use, separate with comma, see references below",
@@ -5196,9 +5192,7 @@ int main (int argc, char **argv)
   uint  increment         = INCREMENT;
   uint  increment_min     = INCREMENT_MIN;
   uint  increment_max     = INCREMENT_MAX;
-  #ifndef OSX
   char *cpu_affinity      = NULL;
-  #endif
   OCL_PTR *ocl            = NULL;
   char *opencl_devices    = NULL;
   char *opencl_platforms  = NULL;
@@ -5361,9 +5355,7 @@ int main (int argc, char **argv)
     {"markov-classic",    no_argument,       0, IDX_MARKOV_CLASSIC},
     {"markov-threshold",  required_argument, 0, IDX_MARKOV_THRESHOLD},
     {"markov-hcstat",     required_argument, 0, IDX_MARKOV_HCSTAT},
-    #ifndef OSX
     {"cpu-affinity",      required_argument, 0, IDX_CPU_AFFINITY},
-    #endif
     {"opencl-devices",    required_argument, 0, IDX_OPENCL_DEVICES},
     {"opencl-platforms",  required_argument, 0, IDX_OPENCL_PLATFORMS},
     {"opencl-device-types", required_argument, 0, IDX_OPENCL_DEVICE_TYPES},
@@ -5672,9 +5664,7 @@ int main (int argc, char **argv)
       case IDX_HEX_CHARSET:       hex_charset       = 1;               break;
       case IDX_HEX_SALT:          hex_salt          = 1;               break;
       case IDX_HEX_WORDLIST:      hex_wordlist      = 1;               break;
-      #ifndef OSX
       case IDX_CPU_AFFINITY:      cpu_affinity      = optarg;          break;
-      #endif
       case IDX_OPENCL_DEVICES:    opencl_devices    = optarg;          break;
       case IDX_OPENCL_PLATFORMS:  opencl_platforms  = optarg;          break;
       case IDX_OPENCL_DEVICE_TYPES:
@@ -6423,12 +6413,10 @@ int main (int argc, char **argv)
    * cpu affinity
    */
 
-  #ifndef OSX
   if (cpu_affinity)
   {
     set_cpu_affinity (cpu_affinity);
   }
-  #endif
 
   if (rp_gen_seed_chgd == 0)
   {
@@ -6543,9 +6531,7 @@ int main (int argc, char **argv)
   logfile_top_uint64 (limit);
   logfile_top_uint64 (skip);
   logfile_top_char   (separator);
-  #ifndef OSX
   logfile_top_string (cpu_affinity);
-  #endif
   logfile_top_string (custom_charset_1);
   logfile_top_string (custom_charset_2);
   logfile_top_string (custom_charset_3);
diff --git a/src/shared.c b/src/shared.c
index de0fb2ead..8ffad9e7b 100644
--- a/src/shared.c
+++ b/src/shared.c
@@ -4235,11 +4235,35 @@ void truecrypt_crc32 (const char *filename, u8 keytab[64])
   myfree (buf);
 }
 
+#ifdef OSX
+int pthread_setaffinity_np (pthread_t thread, size_t cpu_size, cpu_set_t *cpu_set)
+{
+  int core;
+
+  for (core = 0; core < (8 * (int)cpu_size); core++)
+    if (CPU_ISSET(core, cpu_set)) break;
+
+  thread_affinity_policy_data_t policy = { core };
+
+  const int rc = thread_policy_set (pthread_mach_thread_np (thread), THREAD_AFFINITY_POLICY, (thread_policy_t) &policy, 1);
+
+  if (data.quiet == 0)
+  {
+    if (rc != KERN_SUCCESS)
+    {
+      log_error ("ERROR: %s : %d", "thread_policy_set()", rc);
+    }
+  }
+
+  return rc;
+}
+#endif
+
 void set_cpu_affinity (char *cpu_affinity)
 {
   #ifdef WIN
   DWORD_PTR aff_mask = 0;
-  #elif LINUX
+  #elif _POSIX
   cpu_set_t cpuset;
   CPU_ZERO (&cpuset);
   #endif
@@ -4258,7 +4282,7 @@ void set_cpu_affinity (char *cpu_affinity)
       {
         #ifdef WIN
         aff_mask = 0;
-        #elif LINUX
+        #elif _POSIX
         CPU_ZERO (&cpuset);
         #endif
 
@@ -4274,7 +4298,7 @@ void set_cpu_affinity (char *cpu_affinity)
 
       #ifdef WIN
       aff_mask |= 1 << (cpu_id - 1);
-      #elif LINUX
+      #elif _POSIX
       CPU_SET ((cpu_id - 1), &cpuset);
       #endif
 
@@ -4286,7 +4310,7 @@ void set_cpu_affinity (char *cpu_affinity)
   #ifdef WIN
   SetProcessAffinityMask (GetCurrentProcess (), aff_mask);
   SetThreadAffinityMask (GetCurrentThread (), aff_mask);
-  #elif LINUX
+  #elif _POSIX
   pthread_t thread = pthread_self ();
   pthread_setaffinity_np (thread, sizeof (cpu_set_t), &cpuset);
   #endif