diff --git a/vendor/librw/src/rwbase.h b/vendor/librw/src/rwbase.h
index 83a49bb..e30dabe 100644
--- a/vendor/librw/src/rwbase.h
+++ b/vendor/librw/src/rwbase.h
@@ -113,12 +113,15 @@ struct LLLink
 };
 
 #ifndef RW_GL3
+#ifdef __offsetof
+#undef __offsetof
+#endif
 #define	__offsetof(type, field)	(reinterpret_cast <size_t>			\
     (&reinterpret_cast <const volatile char &>	\
                (static_cast<type *> (0)->field)))
 #endif
 #define LLLinkGetData(linkvar,type,entry) \
-  ((type*)(((rw::uint8*)(linkvar))-offsetof(type,entry)))
+    ((type*)(((rw::uint8*)(linkvar))-offsetof(type,entry)))
 
 // Have to be careful since the link might be deleted.
 #define FORLIST(_link, _list) \