Index: include/util/ThreadPool.h
===================================================================
--- a/include/util/ThreadPool.h.orig	2016-11-08 00:35:13.000000000 +0200
+++ b/include/util/ThreadPool.h	2017-03-30 09:58:46.390208931 +0200
@@ -30,6 +30,7 @@
 #include <thread>
 #include <queue>
 #include <future>
+#include <functional>
 
 AUD_NAMESPACE_BEGIN
 /**