--- OLD/libtiff/tiffcomp.h	Thu Jan  1 00:00:00 1970
+++ NEW/libtiff/tiffcomp.h	Thu Jan  1 00:00:00 1970
@@ -64,18 +64,27 @@
 /*
  * Workarounds for BSD lseek definitions.
  */
-#if defined(SYSV) || defined(VMS)
-#if defined(SYSV)
 #include <unistd.h>
-#endif
-#define	L_SET	SEEK_SET
-#define	L_INCR	SEEK_CUR
-#define	L_XTND	SEEK_END
-#endif /* defined(SYSV) || defined(VMS) */
 #ifndef L_SET
-#define L_SET	0
-#define L_INCR	1
-#define L_XTND	2
+#ifdef SEEK_SET
+#define	L_SET SEEK_SET
+#else
+#define L_SET 0
+#endif
+#endif
+#ifndef L_INCR
+#ifdef SEEK_CUR
+#define	L_INCR SEEK_CUR
+#else
+#define L_INCR 1
+#endif
+#endif
+#ifndef L_XTND
+#ifdef SEEK_END
+#define	L_XTND SEEK_END
+#else
+#define L_XTND 2
+#endif
 #endif
 
 /*