diff --git a/common/dist/zlib/gzio.c b/common/dist/zlib/gzio.c
index 034e2af2eb1b..f4970be04378 100644
--- a/common/dist/zlib/gzio.c
+++ b/common/dist/zlib/gzio.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: gzio.c,v 1.2 2006/01/27 00:45:27 christos Exp $	*/
+/*	$NetBSD: gzio.c,v 1.3 2011/05/19 22:23:12 tsutsui Exp $	*/
 
 /* gzio.c -- IO on .gz files
  * Copyright (C) 1995-2005 Jean-loup Gailly.
@@ -76,11 +76,15 @@ typedef struct gz_stream {
 
 
 local gzFile gz_open      OF((const char *path, const char *mode, int  fd));
+#ifndef NO_GZCOMPRESS
 local int do_flush        OF((gzFile file, int flush));
+#endif
 local int    get_byte     OF((gz_stream *s));
 local void   check_header OF((gz_stream *s));
 local int    destroy      OF((gz_stream *s));
+#ifndef NO_GZCOMPRESS
 local void   putLong      OF((FILE *file, uLong x));
+#endif
 local uLong  getLong      OF((gz_stream *s));
 
 /* ===========================================================================
@@ -917,6 +921,7 @@ int ZEXPORT gzdirect (file)
     return s->transparent;
 }
 
+#ifndef NO_GZCOMPRESS
 /* ===========================================================================
    Outputs a long in LSB order to the given file
 */
@@ -930,6 +935,7 @@ local void putLong (file, x)
         x >>= 8;
     }
 }
+#endif
 
 /* ===========================================================================
    Reads a long in LSB order from the given gz_stream. Sets z_err in case
diff --git a/distrib/utils/zcat/Makefile b/distrib/utils/zcat/Makefile
index f99748211008..eaee4101cccf 100644
--- a/distrib/utils/zcat/Makefile
+++ b/distrib/utils/zcat/Makefile
@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.14 2006/01/14 21:15:40 christos Exp $
+# $NetBSD: Makefile,v 1.15 2011/05/19 22:23:12 tsutsui Exp $
 # Small zcat (i.e. for install media)
 #
 # Note: gzio.c is compiled here so that crunchgen will assume
@@ -8,6 +8,7 @@
 
 SRCDIR=		${.CURDIR}/../../../common/dist/zlib
 
+WARNS?=		4
 PROG=		zcat
 NOMAN=		# defined
 
diff --git a/distrib/utils/zcat/zcat.c b/distrib/utils/zcat/zcat.c
index cc3bb4a78aa8..49c623465f9d 100644
--- a/distrib/utils/zcat/zcat.c
+++ b/distrib/utils/zcat/zcat.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: zcat.c,v 1.3 1998/11/12 16:49:47 thorpej Exp $	*/
+/*	$NetBSD: zcat.c,v 1.4 2011/05/19 22:23:12 tsutsui Exp $	*/
 
 /* mini zcat.c -- a minimal zcat using the zlib compression library
  * Copyright (C) 1995-1996 Jean-loup Gailly.
@@ -22,43 +22,45 @@
 
 char *prog;
 
-void error           __P((const char *msg));
-void gz_uncompress   __P((gzFile in, FILE   *out));
-int  main            __P((int argc, char *argv[]));
+void error(const char *msg);
+void gz_uncompress(gzFile in, FILE   *out);
+int  main(int argc, char *argv[]);
 
 /* ===========================================================================
  * Display error message and exit
  */
-void error(msg)
-    const char *msg;
+void error(const char *msg)
 {
-    fprintf(stderr, "%s: %s\n", prog, msg);
-    exit(1);
+
+	fprintf(stderr, "%s: %s\n", prog, msg);
+	exit(EXIT_SUCCESS);
 }
 
 /* ===========================================================================
  * Uncompress input to output then close both files.
  */
-void gz_uncompress(in, out)
-    gzFile in;
-    FILE   *out;
+void gz_uncompress(gzFile in, FILE *out)
 {
-    char buf[BUFLEN];
-    int len;
-    int err;
+	char buf[BUFLEN];
+	int len;
+	int err;
 
-    for (;;) {
-        len = gzread(in, buf, sizeof(buf));
-        if (len < 0) error (gzerror(in, &err));
-        if (len == 0) break;
+	for (;;) {
+		len = gzread(in, buf, sizeof(buf));
+		if (len < 0)
+			error (gzerror(in, &err));
+		if (len == 0)
+			break;
 
-        if ((int)fwrite(buf, 1, (unsigned)len, out) != len) {
-	    error("failed fwrite");
+		if ((int)fwrite(buf, 1, (unsigned)len, out) != len) {
+			error("failed fwrite");
+		}
 	}
-    }
-    if (fclose(out)) error("failed fclose");
+	if (fclose(out))
+		error("failed fclose");
 
-    if (gzclose(in) != Z_OK) error("failed gzclose");
+	if (gzclose(in) != Z_OK)
+		error("failed gzclose");
 }
 
 
@@ -66,39 +68,37 @@ void gz_uncompress(in, out)
  * Usage:  zcat [files...]
  */
 
-int main(argc, argv)
-    int argc;
-    char *argv[];
+int main(int argc, char *argv[])
 {
-    gzFile zfp;
+	gzFile zfp;
 
 	/* save program name and skip */
-    prog = argv[0];
-    argc--, argv++;
+	prog = argv[0];
+	argc--, argv++;
 
 	/* ignore any switches */
 	while (*argv && (**argv == '-')) {
-        argc--, argv++;
-    }
+		argc--, argv++;
+	}
 
-    if (argc == 0) {
+	if (argc == 0) {
 		zfp = gzdopen(fileno(stdin), "rb");
 		if (zfp == NULL)
 			error("can't gzdopen stdin");
 		gz_uncompress(zfp, stdout);
 		return 0;
-    }
+	}
 
 	do {
 		/* file_uncompress(*argv); */
 		zfp = gzopen(*argv, "rb");
 		if (zfp == NULL) {
 			fprintf(stderr, "%s: can't gzopen %s\n", prog, *argv);
-			exit(1);
+			exit(EXIT_FAILURE);
 		}
 		gz_uncompress(zfp, stdout);
 	} while (argv++, --argc);
-    return 0; /* to avoid warning */
+	return 0; /* to avoid warning */
 }
 
 
@@ -106,24 +106,28 @@ int main(argc, argv)
  * XXX: hacks to keep gzio.c from pulling in deflate stuff
  */
 
-int deflateInit2_ (z_streamp strm, int  level, int  method,
-				    int windowBits, int memLevel, int strategy,
-				    const char *version, int stream_size)
+int deflateInit2_(z_streamp strm, int  level, int  method,
+    int windowBits, int memLevel, int strategy,
+    const char *version, int stream_size)
 {
-	return(-1);
+
+	return -1;
 }
 
-int deflate (z_streamp strm, int flush)
+int deflate(z_streamp strm, int flush)
 {
-	return(-1);
+
+	return -1;
 }
 
-int deflateEnd (z_streamp strm)
+int deflateEnd(z_streamp strm)
 {
-	return(-1);
+
+	return -1;
 }
 
-int deflateParams (z_streamp strm, int level, int strategy)
+int deflateParams(z_streamp strm, int level, int strategy)
 {
-	return(Z_STREAM_ERROR);
+
+	return Z_STREAM_ERROR;
 }