diff --git a/src/core/tcp_in.c b/src/core/tcp_in.c
index 913951d4..1268276d 100644
--- a/src/core/tcp_in.c
+++ b/src/core/tcp_in.c
@@ -1544,9 +1544,12 @@ tcp_receive(struct tcp_pcb *pcb)
             if (next &&
                 TCP_SEQ_GT(seqno + tcplen,
                            next->tcphdr->seqno)) {
-              /* inseg cannot have FIN here (already processed above) */
               inseg.len = (u16_t)(next->tcphdr->seqno - seqno);
+#if ESP_LWIP
+              if (TCPH_FLAGS(inseg.tcphdr) & TCP_SYN || TCPH_FLAGS(inseg.tcphdr) & TCP_FIN) {
+#else
               if (TCPH_FLAGS(inseg.tcphdr) & TCP_SYN) {
+#endif
                 inseg.len -= 1;
               }
               pbuf_realloc(inseg.p, inseg.len);