diff --git a/lib/core-net/wsi-timeout.c b/lib/core-net/wsi-timeout.c
index bbaed54c8..b72f134f5 100644
--- a/lib/core-net/wsi-timeout.c
+++ b/lib/core-net/wsi-timeout.c
@@ -206,14 +206,15 @@ lws_validity_cb(lws_sorted_usec_list_t *sul)
 
 	if (wsi->validity_hup) {
 		lwsl_wsi_info(wsi, "validity too old");
-		struct lws_context_per_thread *pt = &wsi->a.context->pt[(int)wsi->tsi];
+		struct lws_context *cx = wsi->a.context;
+		struct lws_context_per_thread *pt = &cx->pt[(int)wsi->tsi];
 
-		lws_context_lock(wsi->a.context, __func__);
+		lws_context_lock(cx, __func__);
 		lws_pt_lock(pt, __func__);
 		__lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS,
 				     "validity timeout");
 		lws_pt_unlock(pt);
-		lws_context_unlock(wsi->a.context);
+		lws_context_unlock(cx);
 		return;
 	}