diff --git a/registration/include/pcl/registration/impl/ndt_2d.hpp b/registration/include/pcl/registration/impl/ndt_2d.hpp
index 880520969be..1194d8fc8b9 100644
--- a/registration/include/pcl/registration/impl/ndt_2d.hpp
+++ b/registration/include/pcl/registration/impl/ndt_2d.hpp
@@ -358,6 +358,7 @@ namespace Eigen
   template<typename PointT> struct NumTraits<pcl::ndt2d::NormalDist<PointT> >
   {
     typedef double Real;
+    typedef double Literal;
     static Real dummy_precision () { return 1.0; }
     enum {
       IsComplex = 0,