diff --git a/lsb-build/headers/stddef.h b/lsb-build/headers/stddef.h
index 15a0968..98e824f 100644
--- a/lsb-build/headers/stddef.h
+++ b/lsb-build/headers/stddef.h
@@ -7,7 +7,7 @@ extern "C" {
 #endif
 
 
-#define offsetof(TYPE,MEMBER)	((size_t)&((TYPE*)0)->MEMBER)
+#define offsetof(TYPE,MEMBER)	__builtin_offsetof(TYPE,MEMBER)
 
 #if !defined(__cplusplus)