diff --git a/Det/OTDet/include/OTDet/OTWireTraj.h b/Det/OTDet/include/OTDet/OTWireTraj.h
index d10c81fb63ca33c8f17cb37104b67cac0de13edb..03c8b1ebc65a0a40761607bd7afd55413d9f3fa9 100644
--- a/Det/OTDet/include/OTDet/OTWireTraj.h
+++ b/Det/OTDet/include/OTDet/OTWireTraj.h
@@ -13,6 +13,7 @@
 
 #include "GaudiKernel/SystemOfUnits.h"
 #include "Kernel/Trajectory.h"
+#include "Math/DisplacementVector3D.h"
 #include <boost/pool/poolfwd.hpp>
 
 /*****************************/