diff --git a/gtsam_unstable/linear/RawQP.h b/gtsam_unstable/linear/RawQP.h
index 2e436e2a8..d5c1eb240 100644
--- a/gtsam_unstable/linear/RawQP.h
+++ b/gtsam_unstable/linear/RawQP.h
@@ -9,6 +9,7 @@
 #include <unordered_map>
 #include <gtsam/inference/Symbol.h>
 #include <boost/fusion/sequence.hpp>
+#include <boost/fusion/include/vector.hpp>
 
 namespace gtsam {
 class RawQP {