Index: in_pcb.c
===================================================================
RCS file: /cvs/src/sys/netinet/in_pcb.c,v
retrieving revision 1.261
diff -u -p -r1.261 in_pcb.c
--- in_pcb.c	14 Mar 2022 22:38:43 -0000	1.261
+++ in_pcb.c	19 Mar 2022 12:54:55 -0000
@@ -893,11 +893,13 @@ in_pcbselsrc(struct in_addr **insrc, str
 	}
 
 	/*
-	 * If the destination address is multicast and an outgoing
-	 * interface has been set as a multicast option, use the
-	 * address of that interface as our source address.
+         * If the destination address is multicast or limited
+         * broadcast (255.255.255.255) and an outgoing interface has
+         * been set as a multicast option, use the address of that
+         * interface as our source address.
 	 */
-	if (IN_MULTICAST(sin->sin_addr.s_addr) && mopts != NULL) {
+	if ((IN_MULTICAST(sin->sin_addr.s_addr) || 
+	    sin->sin_addr.s_addr == INADDR_BROADCAST) && mopts != NULL) {
 		struct ifnet *ifp;
 
 		ifp = if_get(mopts->imo_ifidx);