diff --git a/usr.sbin/wake/wake.8 b/usr.sbin/wake/wake.8
index a837ca644afb..dcce06439f67 100644
--- a/usr.sbin/wake/wake.8
+++ b/usr.sbin/wake/wake.8
@@ -1,4 +1,4 @@
-.\" $NetBSD: wake.8,v 1.7 2010/01/03 19:04:26 wiz Exp $
+.\" $NetBSD: wake.8,v 1.8 2010/01/04 11:34:39 mbalmer Exp $
 .\"
 .\" Copyright (c) 2009, 2010 Marc Balmer <marc@msys.ch>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd January 3, 2010
+.Dd January 4, 2010
 .Dt WAKE 8
 .Os
 .Sh NAME
@@ -35,13 +35,12 @@ WoL functionality is generally enabled in a machine's BIOS
 and can be used to power on machines from a remote system without
 having physical access to them.
 .Pp
-If
 .Ar interface
-is an Ethernet interface of the local machine, it is used to send the
+is an Ethernet interface of the local machine and is used to send the
 Wake on LAN frames over it.
-Else
-.Nm
-uses the first Ethernet device found in the system.
+If there is only one Ethernet device available that is up and running, then the
+.Ar interface
+argument can be omitted.
 .Ar lladdr
 is the link layer address of the remote machine.
 This can be specified as the actual hardware address
diff --git a/usr.sbin/wake/wake.c b/usr.sbin/wake/wake.c
index 4cc1b109d135..49f0f741e923 100644
--- a/usr.sbin/wake/wake.c
+++ b/usr.sbin/wake/wake.c
@@ -1,4 +1,4 @@
-/* $NetBSD: wake.c,v 1.10 2010/01/03 17:58:14 mbalmer Exp $ */
+/* $NetBSD: wake.c,v 1.11 2010/01/04 11:34:39 mbalmer Exp $ */
 
 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010 Marc Balmer <marc@msys.ch>
@@ -117,6 +117,7 @@ find_ether(char *dst, size_t len)
 {
 	struct ifaddrs *ifap, *ifa;
 	struct sockaddr_dl *sdl = NULL;
+	int nifs;
 
 	if (dst == NULL || len == 0)
 		return 0;
@@ -125,18 +126,18 @@ find_ether(char *dst, size_t len)
 		return -1;
 
 	/* XXX also check the link state */
-	for (ifa = ifap; ifa; ifa = ifa->ifa_next)
+	for (nifs = 0, ifa = ifap; ifa; ifa = ifa->ifa_next)
 		if (ifa->ifa_addr->sa_family == AF_LINK &&
 		    ifa->ifa_flags & IFF_UP && ifa->ifa_flags & IFF_RUNNING) {
 			sdl = (struct sockaddr_dl *)ifa->ifa_addr;
 			if (sdl->sdl_type == IFT_ETHER) {
 				strlcpy(dst, ifa->ifa_name, len);
-				break;
+				nifs++;
 			}
 		}
 
 	freeifaddrs(ifap);
-	return 0;
+	return nifs == 1 ? 0 : -1;
 }
 
 static int