diff --git a/src/include/lwip/tcp.h b/src/include/lwip/tcp.h
index b2ee445a..1a365f3e 100644
--- a/src/include/lwip/tcp.h
+++ b/src/include/lwip/tcp.h
@@ -333,7 +333,7 @@ void             tcp_err     (struct tcp_pcb *pcb, tcp_err_fn err);
   (((struct tcp_pcb_listen *)(pcb))->accepts_pending--); } while(0)
 #else  /* TCP_LISTEN_BACKLOG */
 #define          tcp_accepted(pcb) LWIP_ASSERT("pcb->state == LISTEN (called for wrong pcb?)", \
-                                               pcb->state == LISTEN)
+                                               (pcb)->state == LISTEN)
 #endif /* TCP_LISTEN_BACKLOG */
 
 void             tcp_recved  (struct tcp_pcb *pcb, u16_t len);