diff --git a/src/ulib/log/log.h b/src/ulib/log/log.h
index 0ee6ba4..1e7033f 100644
--- a/src/ulib/log/log.h
+++ b/src/ulib/log/log.h
@@ -8,6 +8,7 @@
 #include "ulib/base/location.h"
 #include "logger.h"
 #include "level.h"
+#include <stdlib.h>
 #include <fmt/format.h>
 
 namespace tqcq {
diff --git a/src/ulib/system/thread.cpp b/src/ulib/system/thread.cpp
index 871c3db..87d2203 100644
--- a/src/ulib/system/thread.cpp
+++ b/src/ulib/system/thread.cpp
@@ -13,13 +13,7 @@ pid_t
 GetTid()
 {
     // TODO cache tid
-#if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_12
-    uint64_t tid64;
-    pthread_threadid_np(NULL, &tid64);
-    return static_cast<pid_t>(tid64);
-#else
     return static_cast<pid_t>(::syscall(SYS_gettid));
-#endif
 }
 
 class Thread::Impl {