diff --git a/include/wine/list.h b/include/wine/list.h
index da3ce913c00..97126035123 100644
--- a/include/wine/list.h
+++ b/include/wine/list.h
@@ -227,6 +227,6 @@ static inline void list_move_head( struct list *dst, struct list *src )
 /* get pointer to object containing list element */
 #undef LIST_ENTRY
 #define LIST_ENTRY(elem, type, field) \
-    ((type *)((char *)(elem) - (unsigned long)(&((type *)0)->field)))
+    ((type *)((char *)(elem) - (size_t)(&((type *)0)->field)))
 
 #endif  /* __WINE_SERVER_LIST_H */