diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 64afe71e2129adf79c6505f1ac6b7a644210c873..c1253c2ea4176c3fea8d0c872bce0332bc24cdd4 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -174,8 +174,14 @@ static void mptcp_parse_option(const struct sk_buff *skb,
 		 * the checksum field MUST be ignored.
 		 */
 		if (opsize != expected_opsize &&
-		    opsize != expected_opsize + TCPOLEN_MPTCP_DSS_CHECKSUM)
+		    opsize != expected_opsize + TCPOLEN_MPTCP_DSS_CHECKSUM) {
+			mp_opt->dsn64 = 0;
+			mp_opt->use_map = 0;
+			mp_opt->ack64 = 0;
+			mp_opt->use_ack = 0;
+			mp_opt->data_fin = 0;
 			break;
+		}
 
 		mp_opt->dss = 1;