Index: uspace/lib/posix/stddef.h
===================================================================
--- uspace/lib/posix/stddef.h	(revision 14aa03aefa0b16c9ab45004d2aae1856af366cb4)
+++ uspace/lib/posix/stddef.h	(revision b9a46fc8f6bdb0f4677773cfe10a64cbaa371c49)
@@ -42,4 +42,6 @@
 #endif
 
+#define offsetof(type,member) ((size_t) &(((type *) 0)->member))
+
 typedef ssize_t posix_ptrdiff_t;