diff --git a/drivers/net/cxgb3/cxgb3_main.c b/drivers/net/cxgb3/cxgb3_main.c
index 27e7ef5..d4c4076 100644
--- a/drivers/net/cxgb3/cxgb3_main.c
+++ b/drivers/net/cxgb3/cxgb3_main.c
@@ -443,6 +443,7 @@
 		memset(req, 0, sizeof(*req));
 		req->wr.wr_hi = htonl(V_WR_OP(FW_WROPCODE_FORWARD));
 		OPCODE_TID(req) = htonl(MK_OPCODE_TID(CPL_SMT_WRITE_REQ, i));
+		req->mtu_idx = NMTUS - 1;
 		req->iff = i;
 		t3_mgmt_tx(adap, skb);
 		if (skb == adap->nofail_skb) {