diff -Naur conky-1.10.6.orig/src/luamm.hh conky-1.10.6/src/luamm.hh
--- conky-1.10.6.orig/src/luamm.hh	2016-12-04 16:13:57.000000000 +0100
+++ conky-1.10.6/src/luamm.hh	2017-05-05 12:44:37.525676651 +0200
@@ -27,6 +27,7 @@
 #include <mutex>
 #include <exception>
 #include <stdexcept>
+#include <functional>
 #include <string>
 
 #include <lua.hpp>