diff --git a/opm/grid/cpgrid/Geometry.hpp b/opm/grid/cpgrid/Geometry.hpp
index bcc1f4b87..5280d7b07 100644
--- a/opm/grid/cpgrid/Geometry.hpp
+++ b/opm/grid/cpgrid/Geometry.hpp
@@ -253,7 +253,7 @@ namespace Dune
             }
 
             /// Returns the centroid of the geometry.
-            GlobalCoordinate center() const
+            const GlobalCoordinate& center() const
             {
                 return pos_;
             }
@@ -262,7 +262,7 @@ namespace Dune
             /// J^T_{ij} = (dg_j/du_i)
             /// where g is the mapping from the reference domain,
             /// and {u_i} are the reference coordinates.
-            JacobianTransposed
+            const JacobianTransposed
             jacobianTransposed(const LocalCoordinate& local_coord) const
             {
                 static_assert(mydimension == 3, "");
@@ -298,7 +298,7 @@ namespace Dune
             }
 
             /// @brief Inverse of Jacobian transposed. \see jacobianTransposed().
-            JacobianInverseTransposed
+            const JacobianInverseTransposed
             jacobianInverseTransposed(const LocalCoordinate& local_coord) const
             {
                 JacobianInverseTransposed Jti = jacobianTransposed(local_coord);