diff --git a/cpp/Matrix.h b/cpp/Matrix.h
index ce7527626..a245a1d06 100644
--- a/cpp/Matrix.h
+++ b/cpp/Matrix.h
@@ -83,6 +83,14 @@ inline Vector operator*(const Matrix& A, const Vector & v) {
   return Vector(prod(A,v));
 }
 
+/**
+ * overload * for vector*matrix multiplication (as BOOST does not)
+ */
+inline Vector operator*(const Vector & v, const Matrix& A) {
+  if (A.size1()!=v.size()) throw(std::invalid_argument("Matrix operator* : A.m!=v.size"));
+  return Vector(prod(v,A));
+}
+
 /**
  * overload * for matrix multiplication (as BOOST does not)
  */