diff --git a/net/dccp/input.c b/net/dccp/input.c
index 5e312b0..cb0f5c9 100644
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -300,6 +300,12 @@
 			goto out_invalid_packet;
 		}
 
+                if (dp->dccps_options.dccpo_send_ack_vector &&
+                    dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk,
+                                    DCCP_SKB_CB(skb)->dccpd_seq,
+                                    DCCP_ACKVEC_STATE_RECEIVED))
+                        goto out_invalid_packet; /* FIXME: change error code */
+
 		dp->dccps_isr = DCCP_SKB_CB(skb)->dccpd_seq;
 		dccp_update_gsr(sk, dp->dccps_isr);
 		/*