diff --git a/sys/net/ieee8023ad_lacp.c b/sys/net/ieee8023ad_lacp.c
--- a/sys/net/ieee8023ad_lacp.c
+++ b/sys/net/ieee8023ad_lacp.c
@@ -919,7 +919,8 @@
 	/* send a marker frame down each port to verify the queues are empty */
 	LIST_FOREACH(lp, &lsc->lsc_ports, lp_next) {
 		lp->lp_flags |= LACP_PORT_MARK;
-		lacp_xmit_marker(lp);
+		if (lacp_xmit_marker(lp) != 0)
+			lp->lp_flags &= ~LACP_PORT_MARK;
 	}
 
 	/* set a timeout for the marker frames */