diff --git a/NewKernel_d/include/CGAL/NewKernel_d/LA_eigen/constructors.h b/NewKernel_d/include/CGAL/NewKernel_d/LA_eigen/constructors.h
index 1bb4b2a33ef..1341a28f7df 100644
--- a/NewKernel_d/include/CGAL/NewKernel_d/LA_eigen/constructors.h
+++ b/NewKernel_d/include/CGAL/NewKernel_d/LA_eigen/constructors.h
@@ -92,7 +92,7 @@ namespace CGAL {
 
     struct Initializer_list {
       result_type operator()(std::initializer_list<NT> l) const {
-        return Iterator()(l.size(),l.begin(),l.end());
+        return Iterator()(static_cast<int>(l.size()),l.begin(),l.end());
       }
     };