diff --git a/gtsam/linear/SubgraphBuilder.h b/gtsam/linear/SubgraphBuilder.h
index 5247ea2a2..84a477a5e 100644
--- a/gtsam/linear/SubgraphBuilder.h
+++ b/gtsam/linear/SubgraphBuilder.h
@@ -21,6 +21,7 @@
 #include <gtsam/base/types.h>
 #include <gtsam/dllexport.h>
 
+#include <boost/serialization/version.hpp>
 #include <boost/serialization/nvp.hpp>
 #include <boost/shared_ptr.hpp>