$NetBSD$

--- as/gensym.c.orig	1993-07-10 21:11:38.000000000 +0200
+++ as/gensym.c
@@ -17,7 +17,6 @@ int strcmp P((const char *s1, const char
 #ifdef POSIX_HEADERS_MISSING
 int write P((int fd, const void *buf, unsigned nbytes));
 #else
-#undef NULL
 #include <sys/types.h>
 #include <unistd.h>
 #endif
