diff --git a/dbms/src/Common/MemoryTracker.h b/dbms/src/Common/MemoryTracker.h
index b7324aa468d..0c9910e0605 100644
--- a/dbms/src/Common/MemoryTracker.h
+++ b/dbms/src/Common/MemoryTracker.h
@@ -84,11 +84,7 @@ class MemoryTracker
   * This pointer is set when memory consumption is monitored in current thread.
   * So, you just need to pass it to all the threads that handle one request.
   */
-#if __APPLE__ && __clang__
-extern __thread MemoryTracker * current_memory_tracker;
-#else
 extern thread_local MemoryTracker * current_memory_tracker;
-#endif
 
 /// Convenience methods, that use current_memory_tracker if it is available.
 namespace CurrentMemoryTracker