diff --git a/extmod/modlwip.c b/extmod/modlwip.c
index b53559ed8c..b84b3b7626 100644
--- a/extmod/modlwip.c
+++ b/extmod/modlwip.c
@@ -907,7 +907,7 @@ static const mp_obj_type_t lwip_socket_type;
 
 static void lwip_socket_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
     lwip_socket_obj_t *self = MP_OBJ_TO_PTR(self_in);
-    mp_printf(print, "<socket state=%d timeout=%d incoming=", self->state, self->timeout);
+    mp_printf(print, "<socket state=%d timeout=" UINT_FMT " incoming=", self->state, self->timeout);
     if (self->type == MOD_NETWORK_SOCK_STREAM) {
         mp_printf(print, "%p off=%d>", self->incoming.tcp.pbuf, self->recv_offset);
     } else {