diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp
index c9fe44ed1..2949de169 100644
--- a/src/engine/engine.cpp
+++ b/src/engine/engine.cpp
@@ -22,6 +22,7 @@
 #include <boost/assert.hpp>
 #include <boost/interprocess/sync/named_condition.hpp>
 #include <boost/interprocess/sync/scoped_lock.hpp>
+#include <boost/thread/lock_types.hpp>
 
 #include <algorithm>
 #include <fstream>