diff --git a/Event/xAOD/xAODPFlow/xAODPFlow/versions/FlowElement_v1.h b/Event/xAOD/xAODPFlow/xAODPFlow/versions/FlowElement_v1.h
index 13927118c09435ec0b990dc37bebbe55ec87c7fd..79b43c8094e91e6c19fc26363c809414eadbd020 100644
--- a/Event/xAOD/xAODPFlow/xAODPFlow/versions/FlowElement_v1.h
+++ b/Event/xAOD/xAODPFlow/xAODPFlow/versions/FlowElement_v1.h
@@ -149,5 +149,9 @@ namespace xAOD {
   };
 
 }
+// Declare IParticle as a base class of FlowElement_v1:
+#include "AthContainers/DataVector.h"
+DATAVECTOR_BASE( xAOD::FlowElement_v1, xAOD::IParticle );
+
 
 #endif