diff --git a/cpukit/zlib/ChangeLog b/cpukit/zlib/ChangeLog
index 800670bcef..0141b562d8 100644
--- a/cpukit/zlib/ChangeLog
+++ b/cpukit/zlib/ChangeLog
@@ -1,3 +1,8 @@
+2005-10-30	Ralf Corsepius <ralf.corsepius@rtems.org>
+
+	* zconf.h: Hard-code using unistd.h.
+	Hard-code Z_PREFIX.
+
 2005-10-28	Ralf Corsepius <ralf.corsepius@rtems.org>
 
 	* zconf.in.h: Remove (Unused).
diff --git a/cpukit/zlib/zconf.h b/cpukit/zlib/zconf.h
index ea939082ab..1060bcdc69 100644
--- a/cpukit/zlib/zconf.h
+++ b/cpukit/zlib/zconf.h
@@ -8,6 +8,8 @@
 #ifndef ZCONF_H
 #define ZCONF_H
 
+#define Z_PREFIX 1
+
 /*
  * If you *really* need a unique prefix for all types and library functions,
  * compile with -DZ_PREFIX. The "standard" zlib should be compiled without it.
@@ -291,7 +293,7 @@ typedef uLong FAR uLongf;
    typedef Byte       *voidp;
 #endif
 
-#if 0           /* HAVE_UNISTD_H -- this line is updated by ./configure */
+#if 1           /* HAVE_UNISTD_H -- this line is updated by ./configure */
 #  include <sys/types.h> /* for off_t */
 #  include <unistd.h>    /* for SEEK_* and off_t */
 #  ifdef VMS