diff --git a/src/atomicvar.h b/src/atomicvar.h
index 3489972d..0655ba5c 100644
--- a/src/atomicvar.h
+++ b/src/atomicvar.h
@@ -51,7 +51,7 @@
 #ifndef __ATOMIC_VAR_H
 #define __ATOMIC_VAR_H
 
-#if defined(__ATOMIC_RELAXED)
+#if defined(__ATOMIC_RELAXED) && (!defined(__clang__) || __apple_build_version__ > 4210057)
 /* Implementation using __atomic macros. */
 
 #define atomicIncr(var,count,mutex) __atomic_add_fetch(&var,(count),__ATOMIC_RELAXED)