diff --git a/src/validationinterface.h b/src/validationinterface.h
index 094eccf..8c5fe43 100644
--- a/src/validationinterface.h
+++ b/src/validationinterface.h
@@ -8,6 +8,7 @@
 
 #include <boost/signals2/signal.hpp>
 #include <boost/shared_ptr.hpp>
+#include <boost/bind.hpp>
 
 class CBlock;
 struct CBlockLocator;