diff --git a/src/core/tcp_in.c b/src/core/tcp_in.c
index 1edda937..c55da787 100644
--- a/src/core/tcp_in.c
+++ b/src/core/tcp_in.c
@@ -1021,7 +1021,7 @@ tcp_receive(struct tcp_pcb *pcb)
       }
       cseg->p = NULL;
     }
-    if (flags & TCP_FIN) {
+    if (TCPH_FLAGS(cseg->tcphdr) & TCP_FIN) {
       LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_receive: dequeued FIN.\n"));
       recv_flags = TF_GOT_FIN;
     }