diff --git a/src/OpenMesh/Core/Geometry/VectorT.hh b/src/OpenMesh/Core/Geometry/VectorT.hh
index 713637e9..b79882b4 100644
--- a/src/OpenMesh/Core/Geometry/VectorT.hh
+++ b/src/OpenMesh/Core/Geometry/VectorT.hh
@@ -251,7 +251,7 @@ VectorT<double,3>::operator%(const VectorT<double,3>& _rhs) const
 /// \relates OpenMesh::VectorT
 /// scalar * vector
 template<typename Scalar1, typename Scalar2,int N>
-inline VectorT<Scalar1,N> operator*(Scalar2 _s, const VectorT<Scalar1,N> _v) {
+inline VectorT<Scalar1,N> operator*(Scalar2 _s, const VectorT<Scalar1,N>& _v) {
   return _v*_s;
 }