diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index acad61c70de9..10347c9b4dff 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -34,7 +34,7 @@
 
 /* MPTCP suboption lengths */
 #define TCPOLEN_MPTCP_MPC_SYN          12
-#define TCPOLEN_MPTCP_MPC_SYNACK       20
+#define TCPOLEN_MPTCP_MPC_SYNACK       12
 #define TCPOLEN_MPTCP_MPC_ACK          20
 #define TCPOLEN_MPTCP_MPJ_SYN          12
 #define TCPOLEN_MPTCP_MPJ_SYNACK       16
--- >8 ---