diff --git a/src/core/SkSemaphore.cpp b/src/core/SkSemaphore.cpp
index 10f2975f83..55d77d2c96 100644
--- a/src/core/SkSemaphore.cpp
+++ b/src/core/SkSemaphore.cpp
@@ -9,10 +9,10 @@
 #include "src/core/SkLeanWindows.h"
 
 #if defined(SK_BUILD_FOR_MAC) || defined(SK_BUILD_FOR_IOS)
-    #include <mach/mach.h>
+    #include <dispatch/dispatch.h>
 
     // We've got to teach TSAN that there is a happens-before edge between
-    // semaphore_signal() and semaphore_wait().
+    // dispatch_semaphore_signal() and dispatch_semaphore_wait().
     #if __has_feature(thread_sanitizer)
         extern "C" void AnnotateHappensBefore(const char*, int, void*);
         extern "C" void AnnotateHappensAfter (const char*, int, void*);
@@ -22,28 +22,22 @@
     #endif
 
     struct SkSemaphore::OSSemaphore {
-        semaphore_t fSemaphore;
+        dispatch_semaphore_t fSemaphore;
 
         OSSemaphore()  {
-            semaphore_create(mach_task_self(), &fSemaphore, SYNC_POLICY_LIFO, 0/*initial count*/);
+            fSemaphore = dispatch_semaphore_create(0/*initial count*/);
         }
-        ~OSSemaphore() { semaphore_destroy(mach_task_self(), fSemaphore); }
+        ~OSSemaphore() { dispatch_release(fSemaphore); }
 
         void signal(int n) {
-            while (n --> 0) {
+            while (n-- > 0) {
                 AnnotateHappensBefore(__FILE__, __LINE__, &fSemaphore);
-                semaphore_signal(fSemaphore);
+                dispatch_semaphore_signal(fSemaphore);
             }
         }
         void wait() {
-            while (true) {
-                kern_return_t result = semaphore_wait(fSemaphore);
-                if (result == KERN_SUCCESS) {
-                    AnnotateHappensAfter(__FILE__, __LINE__, &fSemaphore);
-                    return;
-                }
-                SkASSERT(result == KERN_ABORTED);
-            }
+            dispatch_semaphore_wait(fSemaphore, DISPATCH_TIME_FOREVER);
+            AnnotateHappensAfter(__FILE__, __LINE__, &fSemaphore);
         }
     };
 #elif defined(SK_BUILD_FOR_WIN)