diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h
index 3c8c59471bc1..b06c2d02ec84 100644
--- a/include/net/inet_connection_sock.h
+++ b/include/net/inet_connection_sock.h
@@ -135,7 +135,7 @@ struct inet_connection_sock {
 	u32			  icsk_user_timeout;
 
 	u64			  icsk_ca_priv[104 / sizeof(u64)];
-#define ICSK_CA_PRIV_SIZE      (13 * sizeof(u64))
+#define ICSK_CA_PRIV_SIZE	  sizeof_field(struct inet_connection_sock, icsk_ca_priv)
 };
 
 #define ICSK_TIME_RETRANS	1	/* Retransmit timer */