diff --git a/include/arpa/inet.h b/include/arpa/inet.h
index fdc770862c31..c6a4d0775fcf 100644
--- a/include/arpa/inet.h
+++ b/include/arpa/inet.h
@@ -148,7 +148,7 @@ uint16_t	 ntohs(uint16_t);
 
 in_addr_t	 inet_addr(const char *);
 /*const*/ char	*inet_ntoa(struct in_addr);
-char			*inet_ntoa_r(struct in_addr, char *buf);
+char		*inet_ntoa_r(struct in_addr, char *buf, socklen_t size);
 const char	*inet_ntop(int, const void * __restrict, char * __restrict,
 		    socklen_t);
 int		 inet_pton(int, const char * __restrict, void * __restrict);
diff --git a/lib/libc/inet/inet_ntoa.c b/lib/libc/inet/inet_ntoa.c
index b75a983a523a..f5d69fac583c 100644
--- a/lib/libc/inet/inet_ntoa.c
+++ b/lib/libc/inet/inet_ntoa.c
@@ -1,4 +1,4 @@
-/*
+/*-
  * Copyright (c) 1983, 1993
  *	The Regents of the University of California.  All rights reserved.
  *
@@ -60,9 +60,10 @@ inet_ntoa(struct in_addr in) {
 }
 
 char *
-inet_ntoa_r(struct in_addr in, char *buf)
+inet_ntoa_r(struct in_addr in, char *buf, socklen_t size)
 {
-	(void) inet_ntop(AF_INET, &in, buf, sizeof("255.255.255.255"));
+
+	(void) inet_ntop(AF_INET, &in, buf, size);
 	return (buf);
 }
 
diff --git a/lib/libc/net/inet.3 b/lib/libc/net/inet.3
index d6428c90142c..af48143d9f68 100644
--- a/lib/libc/net/inet.3
+++ b/lib/libc/net/inet.3
@@ -28,7 +28,7 @@
 .\"     From: @(#)inet.3	8.1 (Berkeley) 6/4/93
 .\" $FreeBSD$
 .\"
-.Dd June 11, 2007
+.Dd June 14, 2007
 .Dt INET 3
 .Os
 .Sh NAME
@@ -62,6 +62,7 @@
 .Fo inet_ntoa_r
 .Fa "struct in_addr in"
 .Fa "char *buf"
+.Fa "socklen_t size"
 .Fc
 .Ft const char *
 .Fo inet_ntop
@@ -156,7 +157,6 @@ The routine
 .Fn inet_ntoa_r
 is the reentrant version of
 .Fn inet_ntoa .
-It requires a buffer large enough to contain an IPv4 address.
 The routine
 .Fn inet_makeaddr
 takes an Internet network number and a local