diff --git a/src/OpenMesh/Core/Geometry/EigenVectorT.hh b/src/OpenMesh/Core/Geometry/EigenVectorT.hh
index fb7c3be3..ce9ffc32 100644
--- a/src/OpenMesh/Core/Geometry/EigenVectorT.hh
+++ b/src/OpenMesh/Core/Geometry/EigenVectorT.hh
@@ -88,7 +88,7 @@ namespace Eigen {
   }
 
   template <typename Derived>
-  MatrixBase<Derived> normalize(MatrixBase<Derived> &x) {
+  MatrixBase<Derived> &normalize(MatrixBase<Derived> &x) {
       x /= x.norm();
       return x;
   }