diff --git a/src/mesh/Boundary.hpp b/src/mesh/Boundary.hpp
index f5164262f5582e2a829c2627df7cb18131fbd65d..de92042e132d2940926f69d3e96c1dbd39451cd7 100644
--- a/src/mesh/Boundary.hpp
+++ b/src/mesh/Boundary.hpp
@@ -19,12 +19,12 @@ class Boundary
     return m_ref_id;
   }
 
-  const Kokkos::View<const unsigned int*> faceList() const
+  const Kokkos::View<const unsigned int*>& faceList() const
   {
     return m_face_id_list;
   }
 
-  const Kokkos::View<const unsigned int*> nodeList() const
+  const Kokkos::View<const unsigned int*>& nodeList() const
   {
     return m_node_id_list;
   }
@@ -32,7 +32,7 @@ class Boundary
   template<typename ConnectivityType>
   Boundary(const ConnectivityType& connectivity,
            const RefId& ref_id,
-           const Kokkos::View<const unsigned int*> face_id_list)
+           const Kokkos::View<const unsigned int*>& face_id_list)
       : m_ref_id(ref_id),
         m_face_id_list(face_id_list)
   {