diff --git Swiften/EventLoop/EventLoop.cpp Swiften/EventLoop/EventLoop.cpp
index afb6858..507de0b 100644
--- Swiften/EventLoop/EventLoop.cpp
+++ Swiften/EventLoop/EventLoop.cpp
@@ -8,6 +8,7 @@
 
 #include <algorithm>
 #include <boost/bind.hpp>
+#include <boost/thread/locks.hpp>
 #include <iostream>
 #include <cassert>