diff --git a/wolfcrypt/src/wc_port.c b/wolfcrypt/src/wc_port.c
index 1d4ba2158..a5b864a95 100644
--- a/wolfcrypt/src/wc_port.c
+++ b/wolfcrypt/src/wc_port.c
@@ -3962,7 +3962,21 @@ char* mystrnstr(const char* s1, const char* s2, unsigned int n)
     {
         if (cond == NULL)
             return BAD_FUNC_ARG;
-    #if defined(__OS2__)
+    #if defined(__MACH__)
+        cond->cond = dispatch_semaphore_create(0);
+        if (cond->cond == NULL)
+            return MEMORY_E;
+
+        /* dispatch_release() fails hard, with Trace/BPT trap signal, if the
+         * sem's internal count is less than the value passed in with
+         * dispatch_semaphore_create().  work around this by initializing
+         * with 0, then incrementing it afterwards.
+         */
+        if (dispatch_semaphore_signal(s->sem) < 0) {
+            dispatch_release(s->sem);
+            return return MEMORY_E;
+        }
+    #elif defined(__OS2__)
         DosCreateMutexSem( NULL, &cond->mutex, 0, FALSE );
         DosCreateEventSem( NULL, &cond->cond, DCE_POSTONE, FALSE );
     #elif defined(__NT__)
@@ -3993,7 +4007,9 @@ char* mystrnstr(const char* s1, const char* s2, unsigned int n)
     {
         if (cond == NULL)
             return BAD_FUNC_ARG;
-    #if defined(__OS2__)
+    #if defined(__MACH__)
+        dispatch_release(cond->cond);
+    #elif defined(__OS2__)
         DosCloseMutexSem(cond->mutex);
         DosCloseEventSem(cond->cond);
     #elif defined(__NT__)
@@ -4013,7 +4029,8 @@ char* mystrnstr(const char* s1, const char* s2, unsigned int n)
     {
         if (cond == NULL)
             return BAD_FUNC_ARG;
-    #if defined(__OS2__)
+    #if defined(__MACH__)
+    #elif defined(__OS2__)
     #elif defined(__NT__)
         if (wc_LockMutex(&cond->mutex) != 0)
             return BAD_MUTEX_E;
@@ -4028,7 +4045,9 @@ char* mystrnstr(const char* s1, const char* s2, unsigned int n)
     {
         if (cond == NULL)
             return BAD_FUNC_ARG;
-    #if defined(__OS2__)
+    #if defined(__MACH__)
+        dispatch_semaphore_signal(cond->cond);
+    #elif defined(__OS2__)
     #elif defined(__NT__)
         if (wc_UnLockMutex(&cond->mutex) != 0)
             return BAD_MUTEX_E;
@@ -4049,7 +4068,9 @@ char* mystrnstr(const char* s1, const char* s2, unsigned int n)
     {
         if (cond == NULL)
             return BAD_FUNC_ARG;
-    #if defined(__OS2__)
+    #if defined(__MACH__)
+        dispatch_semaphore_wait(cond->cond, DISPATCH_TIME_FOREVER);
+    #elif defined(__OS2__)
     #elif defined(__NT__)
         if (wc_UnLockMutex(&cond->mutex) != 0)
             return BAD_MUTEX_E;
diff --git a/wolfssl/wolfcrypt/types.h b/wolfssl/wolfcrypt/types.h
index 2f1dcbfe7..100382712 100644
--- a/wolfssl/wolfcrypt/types.h
+++ b/wolfssl/wolfcrypt/types.h
@@ -1572,7 +1572,20 @@ WOLFSSL_API word32 CheckRunTimeSettings(void);
     #if __WATCOMC__ < 1300
         #define _WCCALLBACK
     #endif
-    #if defined(__NT__)
+    #if defined(__MACH__)
+        #include <dispatch/dispatch.h>
+        #include <pthread.h>
+        typedef struct COND_TYPE {
+            dispatch_semaphore_t cond;
+        } COND_TYPE;
+        typedef void*         THREAD_RETURN;
+        typedef pthread_t     THREAD_TYPE;
+        #define WOLFSSL_COND
+        #define WOLFSSL_THREAD
+        #ifndef HAVE_SELFTEST
+            #define WOLFSSL_THREAD_NO_JOIN
+        #endif
+    #elif defined(__NT__)
         typedef unsigned      THREAD_RETURN;
         typedef uintptr_t     THREAD_TYPE;
         typedef struct COND_TYPE {