diff --git a/osdep.h b/osdep.h
index 2517b1a..32ee94b 100644
--- a/osdep.h
+++ b/osdep.h
@@ -36,6 +36,9 @@
         (type *) ((char *) __mptr - offsetof(type, member));})
 #endif
 
+#define typeof_field(type, field) typeof(((type *)0)->field)
+#define type_check(t1,t2) ((t1*)0 - (t2*)0)
+
 #ifndef MIN
 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
 #endif