diff --git a/src/raw_logging.cc b/src/raw_logging.cc
index 7a7409b..5224f19 100644
--- a/src/raw_logging.cc
+++ b/src/raw_logging.cc
@@ -59,7 +59,8 @@
 # include <unistd.h>
 #endif
 
-#if defined(HAVE_SYSCALL_H) || defined(HAVE_SYS_SYSCALL_H)
+#if (defined(HAVE_SYSCALL_H) || defined(HAVE_SYS_SYSCALL_H)) && \
+    MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_12
 # define safe_write(fd, s, len)  syscall(SYS_write, fd, s, len)
 #else
   // Not so safe, but what can you do?
diff --git a/src/utilities.cc b/src/utilities.cc
index 5c88e58..09b96b2 100644
--- a/src/utilities.cc
+++ b/src/utilities.cc
@@ -238,8 +238,15 @@
 }
 
 pid_t GetTID() {
-  // On Linux and MacOSX, we try to use gettid().
+  // On Linux, and MacOSX prior to 10.12, we try to use gettid(). On
+  // MacOSX 10.12 and later, we use pthread_threadid_np instead, as
+  // syscall is deprecated.
 #if defined OS_LINUX || defined OS_MACOSX
+#if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_12
+  uint64_t tid;
+  pthread_threadid_np(nullptr, &tid);
+  return static_cast<pid_t>(tid);
+#else
 #ifndef __NR_gettid
 #ifdef OS_MACOSX
 #define __NR_gettid SYS_gettid
@@ -261,6 +268,7 @@
     // the value change to "true".
     lacks_gettid = true;
   }
+#endif  // MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_12
 #endif  // OS_LINUX || OS_MACOSX
 
   // If gettid() could not be used, we use one of the following.