diff --git a/lib/libc/gen/confstr.3 b/lib/libc/gen/confstr.3
index 3eac2ab225b3..53100304176a 100644
--- a/lib/libc/gen/confstr.3
+++ b/lib/libc/gen/confstr.3
@@ -1,4 +1,4 @@
-.\"	$NetBSD: confstr.3,v 1.15 2003/08/07 16:42:46 agc Exp $
+.\"	$NetBSD: confstr.3,v 1.16 2006/12/03 00:39:19 christos Exp $
 .\"
 .\" Copyright (c) 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -29,7 +29,7 @@
 .\"
 .\"	@(#)confstr.3	8.1 (Berkeley) 6/4/93
 .\"
-.Dd June 4, 1993
+.Dd December 2, 2006
 .Dt CONFSTR 3
 .Os
 .Sh NAME
@@ -86,7 +86,7 @@ environment variable that finds all the standard utilities.
 .Sh RETURN VALUES
 If the call to
 .Nm confstr
-is not successful, ((size_t)-1) is returned and
+is not successful, is returned and
 .Va errno
 is set appropriately.
 Otherwise, if the variable does not have a configuration defined value,
@@ -124,6 +124,9 @@ The
 .Nm confstr
 function conforms to
 .St -p1003.2-92 .
+.Sh BUGS
+The standards require us to return 0 both on errors, and when the value
+is not set.
 .Sh HISTORY
 The
 .Nm confstr
diff --git a/lib/libc/gen/confstr.c b/lib/libc/gen/confstr.c
index 1cbbc0e46a9e..4641e94635c4 100644
--- a/lib/libc/gen/confstr.c
+++ b/lib/libc/gen/confstr.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: confstr.c,v 1.11 2003/08/07 16:42:46 agc Exp $	*/
+/*	$NetBSD: confstr.c,v 1.12 2006/12/03 00:39:19 christos Exp $	*/
 
 /*-
  * Copyright (c) 1993
@@ -34,7 +34,7 @@
 #if 0
 static char sccsid[] = "@(#)confstr.c	8.1 (Berkeley) 6/4/93";
 #else
-__RCSID("$NetBSD: confstr.c,v 1.11 2003/08/07 16:42:46 agc Exp $");
+__RCSID("$NetBSD: confstr.c,v 1.12 2006/12/03 00:39:19 christos Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -62,33 +62,37 @@ confstr(name, buf, len)
 	int mib[2], sverrno;
 	char *p;
 
+	/*
+	 * POSIX 1003.2 requires errors to return 0 --
+	 * that is *really* useful.
+	 */
 	switch (name) {
 	case _CS_PATH:
 		mib[0] = CTL_USER;
 		mib[1] = USER_CS_PATH;
 		if (sysctl(mib, 2, NULL, &tlen, NULL, 0) == -1)
-			return (size_t)-1;
+			return 0;
 		if (len != 0 && buf != NULL) {
 			if ((p = malloc(tlen)) == NULL)
-				return (size_t)-1;
+				return 0;
 			if (sysctl(mib, 2, p, &tlen, NULL, 0) == -1) {
 				sverrno = errno;
 				free(p);
 				errno = sverrno;
-				return (size_t)-1;
+				return 0;
 			}
 			/*
 			 * POSIX 1003.2 requires partial return of
-			 * the string -- that should be *real* useful.
+			 * the string -- that is even more useful.
 			 */
 			(void)strncpy(buf, p, len - 1);
 			buf[len - 1] = '\0';
 			free(p);
 		}
-		return (tlen + 1);
+		return tlen + 1;
 	default:
 		errno = EINVAL;
-		return (0);
+		return 0;
 	}
 	/* NOTREACHED */
 }