diff --git a/deps/v8/src/base/platform/platform-posix.cc b/deps/v8/src/base/platform/platform-posix.cc
index 252d2137552997..771634e24e9554 100644
--- a/deps/v8/src/base/platform/platform-posix.cc
+++ b/deps/v8/src/base/platform/platform-posix.cc
@@ -321,11 +321,15 @@ int OS::GetCurrentProcessId() {
 
 
 int OS::GetCurrentThreadId() {
-#if defined(ANDROID)
+#if V8_OS_MACOSX
+  return static_cast<int>(pthread_mach_thread_np(pthread_self()));
+#elif V8_OS_LINUX
   return static_cast<int>(syscall(__NR_gettid));
+#elif V8_OS_ANDROID
+  return static_cast<int>(gettid());
 #else
-  return static_cast<int>(syscall(SYS_gettid));
-#endif  // defined(ANDROID)
+  return static_cast<int>(pthread_self());
+#endif
 }
 
 
diff --git a/deps/v8/src/base/platform/platform.h b/deps/v8/src/base/platform/platform.h
index 8a5412626857af..9567572d800356 100644
--- a/deps/v8/src/base/platform/platform.h
+++ b/deps/v8/src/base/platform/platform.h
@@ -35,6 +35,7 @@ namespace std {
 int signbit(double x);
 }
 # endif
+#include <alloca.h>
 #endif
 
 #if V8_OS_QNX