1 files changed, 5 insertions, 2 deletions
diff --git a/extmod/modlwip.c b/extmod/modlwip.c
index 216e81749..1d557a6a8 100644
--- a/extmod/modlwip.c
+++ b/extmod/modlwip.c
@@ -757,8 +757,11 @@ STATIC mp_uint_t lwip_tcp_receive(lwip_socket_obj_t *socket, byte *buf, mp_uint_
                 return 0;
             }
         } else if (socket->state != STATE_CONNECTED) {
-            assert(socket->state < 0);
-            *_errno = error_lookup_table[-socket->state];
+            if (socket->state >= STATE_NEW) {
+                *_errno = MP_ENOTCONN;
+            } else {
+                *_errno = error_lookup_table[-socket->state];
+            }
             return -1;
         }
     }