--- qbittorrent-1.3.1/src/httpserver.h.orig 
+++ qbittorrent-1.3.1/src/httpserver.h 
@@ -22,6 +22,7 @@
 #ifndef HTTPSERVER_H
 #define HTTPSERVER_H
 
+#include <QPair>
 #include <QTcpServer>
 #include <QByteArray>