diff --git a/dune/elasticity/materials/geomexactstvenantkirchhoffmaterial.hh b/dune/elasticity/materials/geomexactstvenantkirchhoffmaterial.hh
index c4714622bc745e11bf09f61332c51e5c2eac2d05..c8640bb5851a7eb0c9a574030d3ae9f77c0455a4 100644
--- a/dune/elasticity/materials/geomexactstvenantkirchhoffmaterial.hh
+++ b/dune/elasticity/materials/geomexactstvenantkirchhoffmaterial.hh
@@ -69,7 +69,7 @@ public:
     //! Evaluate the strain energy
     ReturnType energy(const GridFunction& displace)
     {
-        ctype energy=0;
+        ReturnType energy=0;
         const GridType& grid = this->basis_->getGridView().grid();
 
         ElementIterator eIt = grid.template leafbegin<0>();