diff --git a/dune/elasticity/materials/neohookeanmaterial.hh b/dune/elasticity/materials/neohookeanmaterial.hh
index 723c6644e7ccaf2b2dda8da8e4adfcc94071a6ef..778efc5a6007b218cad92009f4985750e9723cf5 100644
--- a/dune/elasticity/materials/neohookeanmaterial.hh
+++ b/dune/elasticity/materials/neohookeanmaterial.hh
@@ -131,7 +131,7 @@ public:
             }
         }
             
-        return 0.5*energy;
+        return energy;
     }
    
     //! Return the local assembler of the first derivative of the strain energy