diff --git a/src/core/netif.c b/src/core/netif.c
index ccbbe48a..58e64ced 100644
--- a/src/core/netif.c
+++ b/src/core/netif.c
@@ -126,6 +126,9 @@ netif_loopif_init(struct netif *netif)
 #endif
 #if LWIP_IPV6
   netif->output_ip6 = netif_loop_output_ipv6;
+#endif
+#if LWIP_LOOPIF_MCAST
+  netif->flags |= NETIF_FLAG_IGMP;
 #endif
   return ERR_OK;
 }
diff --git a/src/include/lwip/opt.h b/src/include/lwip/opt.h
index 3615cf41..6de94bb3 100644
--- a/src/include/lwip/opt.h
+++ b/src/include/lwip/opt.h
@@ -1424,6 +1424,13 @@
 #define LWIP_HAVE_LOOPIF                LWIP_NETIF_LOOPBACK
 #endif
 
+/**
+* LWIP_LOOPIF_MCAST==1: Support multicast on loop interface (127.0.0.1).
+*/
+#ifndef LWIP_LOOPIF_MCAST
+#define LWIP_LOOPIF_MCAST               0
+#endif
+
 /*
    ------------------------------------
    ---------- SLIPIF options ----------