diff --git a/lib/sockopt.c b/lib/sockopt.c
index 257271bc0b..d8204936f9 100644
--- a/lib/sockopt.c
+++ b/lib/sockopt.c
@@ -219,6 +219,7 @@ setsockopt_ipv6_tclass(int sock, int tclass)
 int
 setsockopt_ipv4_multicast(int sock,
 			int optname, 
+			struct in_addr if_addr,
 			unsigned int mcast_addr,
 			unsigned int ifindex)
 {
@@ -279,18 +280,20 @@ setsockopt_ipv4_multicast(int sock,
 #elif defined(HAVE_BSD_STRUCT_IP_MREQ_HACK) /* #if OS_TYPE */ 
   /* standard BSD API */
 
-  struct in_addr m;
   struct ip_mreq mreq;
   int ret;
 
   assert(optname == IP_ADD_MEMBERSHIP || optname == IP_DROP_MEMBERSHIP);
 
-  m.s_addr = htonl(ifindex);
 
   memset (&mreq, 0, sizeof(mreq));
   mreq.imr_multiaddr.s_addr = mcast_addr;
-  mreq.imr_interface = m;
-  
+#if !defined __OpenBSD__
+  mreq.imr_interface.s_addr = htonl (ifindex);
+#else
+  mreq.imr_interface.s_addr = if_addr.s_addr;
+#endif
+
   ret = setsockopt (sock, IPPROTO_IP, optname, (void *)&mreq, sizeof(mreq));
   if ((ret < 0) && (optname == IP_ADD_MEMBERSHIP) && (errno == EADDRINUSE))
     {
@@ -318,7 +321,7 @@ setsockopt_ipv4_multicast(int sock,
  * Set IP_MULTICAST_IF socket option in an OS-dependent manner.
  */
 int
-setsockopt_ipv4_multicast_if(int sock,
+setsockopt_ipv4_multicast_if(int sock, struct in_addr if_addr,
 			unsigned int ifindex)
 {
 
@@ -336,7 +339,11 @@ setsockopt_ipv4_multicast_if(int sock,
 #elif defined(HAVE_BSD_STRUCT_IP_MREQ_HACK)
   struct in_addr m;
 
-  m.s_addr = htonl(ifindex);
+#if !defined __OpenBSD__
+  m.s_addr = htonl (ifindex);
+#else
+  m.s_addr = if_addr.s_addr;
+#endif
 
   return setsockopt (sock, IPPROTO_IP, IP_MULTICAST_IF, (void *)&m, sizeof(m));
 #else
diff --git a/lib/sockopt.h b/lib/sockopt.h
index cb14efc7ba..a597314c3d 100644
--- a/lib/sockopt.h
+++ b/lib/sockopt.h
@@ -83,9 +83,10 @@ extern int setsockopt_ipv6_tclass (int, int);
   (((af) == AF_INET) : SOPT_SIZE_CMSG_IFINDEX_IPV4() \
                     ? SOPT_SIZE_CMSG_PKTINFO_IPV6())
 
-extern int setsockopt_ipv4_multicast_if(int sock,
+extern int setsockopt_ipv4_multicast_if(int sock, struct in_addr if_addr,
 			             unsigned int ifindex);
 extern int setsockopt_ipv4_multicast(int sock, int optname,
+                                     struct in_addr if_addr,
                                      unsigned int mcast_addr,
 			             unsigned int ifindex);
 extern int setsockopt_ipv4_tos(int sock, int tos);
diff --git a/ospfd/ospf_network.c b/ospfd/ospf_network.c
index 2f167a50a5..9f516d7390 100644
--- a/ospfd/ospf_network.c
+++ b/ospfd/ospf_network.c
@@ -53,7 +53,7 @@ ospf_if_add_allspfrouters (struct ospf *top, struct prefix *p,
   int ret;
   
   ret = setsockopt_ipv4_multicast (top->fd, IP_ADD_MEMBERSHIP,
-                                   htonl (OSPF_ALLSPFROUTERS),
+                                   p->u.prefix4, htonl (OSPF_ALLSPFROUTERS),
                                    ifindex);
   if (ret < 0)
     zlog_warn ("can't setsockopt IP_ADD_MEMBERSHIP (fd %d, addr %s, "
@@ -74,7 +74,7 @@ ospf_if_drop_allspfrouters (struct ospf *top, struct prefix *p,
   int ret;
 
   ret = setsockopt_ipv4_multicast (top->fd, IP_DROP_MEMBERSHIP,
-                                   htonl (OSPF_ALLSPFROUTERS),
+                                   p->u.prefix4, htonl (OSPF_ALLSPFROUTERS),
                                    ifindex);
   if (ret < 0)
     zlog_warn ("can't setsockopt IP_DROP_MEMBERSHIP (fd %d, addr %s, "
@@ -95,7 +95,7 @@ ospf_if_add_alldrouters (struct ospf *top, struct prefix *p, unsigned int
   int ret;
 
   ret = setsockopt_ipv4_multicast (top->fd, IP_ADD_MEMBERSHIP,
-                                   htonl (OSPF_ALLDROUTERS),
+                                   p->u.prefix4, htonl (OSPF_ALLDROUTERS),
                                    ifindex);
   if (ret < 0)
     zlog_warn ("can't setsockopt IP_ADD_MEMBERSHIP (fd %d, addr %s, "
@@ -116,7 +116,7 @@ ospf_if_drop_alldrouters (struct ospf *top, struct prefix *p, unsigned int
   int ret;
 
   ret = setsockopt_ipv4_multicast (top->fd, IP_DROP_MEMBERSHIP,
-                                   htonl (OSPF_ALLDROUTERS),
+                                   p->u.prefix4, htonl (OSPF_ALLDROUTERS),
                                    ifindex);
   if (ret < 0)
     zlog_warn ("can't setsockopt IP_DROP_MEMBERSHIP (fd %d, addr %s, "
@@ -151,7 +151,7 @@ ospf_if_ipmulticast (struct ospf *top, struct prefix *p, unsigned int ifindex)
     zlog_warn ("can't setsockopt IP_MULTICAST_TTL(1) for fd %d: %s",
 	       top->fd, safe_strerror (errno));
 
-  ret = setsockopt_ipv4_multicast_if (top->fd, ifindex);
+  ret = setsockopt_ipv4_multicast_if (top->fd, p->u.prefix4, ifindex);
   if (ret < 0)
     zlog_warn("can't setsockopt IP_MULTICAST_IF(fd %d, addr %s, "
 	      "ifindex %u): %s",
diff --git a/ripd/rip_interface.c b/ripd/rip_interface.c
index 6748e197da..4499966ad0 100644
--- a/ripd/rip_interface.c
+++ b/ripd/rip_interface.c
@@ -80,6 +80,7 @@ ipv4_multicast_join (int sock,
 
   ret = setsockopt_ipv4_multicast (sock,
 				   IP_ADD_MEMBERSHIP, 
+				   ifa,
 				   group.s_addr, 
 				   ifindex); 
 
@@ -101,6 +102,7 @@ ipv4_multicast_leave (int sock,
 
   ret = setsockopt_ipv4_multicast (sock,
 				   IP_DROP_MEMBERSHIP, 
+				   ifa,
 				   group.s_addr, 
 				   ifindex);
 
@@ -136,9 +138,13 @@ rip_interface_new (void)
 void
 rip_interface_multicast_set (int sock, struct connected *connected)
 {
+  struct in_addr addr;
+
   assert (connected != NULL);
-  
-  if (setsockopt_ipv4_multicast_if (sock, connected->ifp->ifindex) < 0)
+
+  addr = CONNECTED_ID(connected)->u.prefix4;
+
+  if (setsockopt_ipv4_multicast_if (sock, addr, connected->ifp->ifindex) < 0)
     {
       zlog_warn ("Can't setsockopt IP_MULTICAST_IF on fd %d to "
 		 "ifindex %d for interface %s",