diff --git a/src/include/lwip/priv/tcp_priv.h b/src/include/lwip/priv/tcp_priv.h
index 72f9126d..92e58244 100644
--- a/src/include/lwip/priv/tcp_priv.h
+++ b/src/include/lwip/priv/tcp_priv.h
@@ -128,7 +128,9 @@ err_t            tcp_process_refused_data(struct tcp_pcb *pcb);
 #define TCP_SLOW_INTERVAL      (2*TCP_TMR_INTERVAL)  /* the coarse grained timeout in milliseconds */
 #endif /* TCP_SLOW_INTERVAL */
 
+#ifndef TCP_FIN_WAIT_TIMEOUT
 #define TCP_FIN_WAIT_TIMEOUT 20000 /* milliseconds */
+#endif /* TCP_FIN_WAIT_TIMEOUT */
 #define TCP_SYN_RCVD_TIMEOUT 20000 /* milliseconds */
 
 #define TCP_OOSEQ_TIMEOUT        6U /* x RTO */