diff --git a/include/boost/numeric/ublas/operation.hpp b/include/boost/numeric/ublas/operation.hpp
index 98590ef7..f99b9926 100644
--- a/include/boost/numeric/ublas/operation.hpp
+++ b/include/boost/numeric/ublas/operation.hpp
@@ -21,7 +21,7 @@
 #ifndef BOOST_UBLAS_OPERATION_H
 #define BOOST_UBLAS_OPERATION_H
 
-#include <boost/numeric/ublas/traits.hpp>
+#include <boost/numeric/ublas/matrix_proxy.hpp>
 
 // axpy-based products
 // Alexei Novakov had a lot of ideas to improve these. Thanks.