diff --git a/Utilities/cmzlib/zconf.h b/Utilities/cmzlib/zconf.h
index 03a9431c8b..6e12b90f51 100644
--- a/Utilities/cmzlib/zconf.h
+++ b/Utilities/cmzlib/zconf.h
@@ -284,7 +284,7 @@ typedef uLong FAR uLongf;
    typedef Byte       *voidp;
 #endif
 
-#if 0           /* HAVE_UNISTD_H -- this line is updated by ./configure */
+#if !defined(_WIN32)
 #  include <sys/types.h> /* for off_t */
 #  include <unistd.h>    /* for SEEK_* and off_t */
 #  ifdef VMS