--- unix/unix.c.orig	Fri Jul 22 00:37:08 1994
+++ unix/unix.c	Fri Apr  5 22:26:10 2013
@@ -18,7 +18,7 @@
 #include "constant.h"
 #include "types.h"
 
-#ifdef unix
+#ifdef __OpenBSD__
 
 #if defined(SYS_V) && defined(lint)
 /* for AIX, prevent hundreds of unnecessary lint errors, must define before
@@ -43,7 +43,7 @@ typedef struct { int stuff; } fpvmach;
 #include <sys/param.h>
 #endif
 
-#ifdef __linux__
+#ifdef __OpenBSD__
 #include <sys/time.h>
 #include <sys/types.h>
 #include <unistd.h>
@@ -121,12 +121,12 @@ static Ioctl(i, l, p) char *p; { return 0; }
 int check_input(microsec)
 int microsec;
 {
-#if defined(USG) && !defined(M_XENIX) && !defined(__linux__)
+#if defined(USG) && !defined(M_XENIX) && !defined(__OpenBSD__)
   int arg, result;
 #else
   struct timeval tbuf;
   int ch;
-#if defined(BSD4_3) || defined(M_XENIX) || defined(__linux__)
+#if defined(BSD4_3) || defined(M_XENIX) || defined(__OpenBSD__)
   fd_set smask;
 #else
   int smask;
@@ -134,10 +134,10 @@ int microsec;
 #endif
 
   /* Return true if a read on descriptor 1 will not block. */
-#if !defined(USG) || defined(M_XENIX) || defined(__linux__)
+#if !defined(USG) || defined(M_XENIX) || defined(__OpenBSD__)
   tbuf.tv_sec = 0;
   tbuf.tv_usec = microsec;
-#if defined(BSD4_3) || defined(M_XENIX) || defined(__linux__)
+#if defined(BSD4_3) || defined(M_XENIX) || defined(__OpenBSD__)
   FD_ZERO(&smask);
   FD_SET(fileno(stdin), &smask);
   if (select(1, &smask, (fd_set *)0, (fd_set *)0, &tbuf) == 1)
