$NetBSD$

--- Telegram/lib_base/base/observer.h.orig	2020-02-14 23:27:20.968340772 +0000
+++ Telegram/lib_base/base/observer.h
@@ -9,6 +9,7 @@
 #include <vector>
 #include <deque>
 #include <rpl/producer.h>
+#include "base/base_pch.h"
 #include "base/type_traits.h"
 
 namespace base {