diff --git a/sys/man/8/dhcpd b/sys/man/8/dhcpd
index 9917772c3..b61c5abdb 100644
--- a/sys/man/8/dhcpd
+++ b/sys/man/8/dhcpd
@@ -159,6 +159,9 @@ an SMTP mail server
 the default boot file;
 see
 .IR ndb (6)
+.TP
+.B swap
+used by Unix machines for boot NFS server
 .PD
 .PP
 .I Dhcpd
diff --git a/sys/src/cmd/ip/dhcpd/dhcpd.c b/sys/src/cmd/ip/dhcpd/dhcpd.c
index f7a57c180..b39feb7b6 100644
--- a/sys/src/cmd/ip/dhcpd/dhcpd.c
+++ b/sys/src/cmd/ip/dhcpd/dhcpd.c
@@ -1186,6 +1186,9 @@ miscoptions(Req *rp, uchar *ip)
 		case OBnetbiosns:
 			a[na++] = "@wins";
 			break;
+		case OBswapserver:
+			a[na++] = "@swap";
+			break;
 		case OBsmtpserver:
 			a[na++] = "@smtp";
 			break;
@@ -1256,6 +1259,10 @@ miscoptions(Req *rp, uchar *ip)
 			j = lookupserver("www", addrs, nelem(addrs), t);
 			addrsopt(rp, OBwwwserver, addrs, j);
 			break;
+		case OBswapserver:
+			j = lookupserver("swap", addrs, nelem(addrs), t);
+			addrsopt(rp, OBswapserver, addrs, j);
+			break;
 		case OBntpserver:
 			j = lookupserver("ntp", addrs, nelem(addrs), t);
 			addrsopt(rp, OBntpserver, addrs, j);