diff --git a/plugins/generic-sessions/protocol_lws_messageboard.c b/plugins/generic-sessions/protocol_lws_messageboard.c
index 3c20c90f..de65ad70 100644
--- a/plugins/generic-sessions/protocol_lws_messageboard.c
+++ b/plugins/generic-sessions/protocol_lws_messageboard.c
@@ -373,7 +373,7 @@ callback_messageboard(struct lws *wsi, enum lws_callback_reasons reason,
 
 	default:
 passthru:
-		if (!pss)
+		if (!pss || !vhd)
 			break;
 		return vhd->gsp->callback(wsi, reason, pss->pss_gs, in, len);
 	}