diff --git a/MaterialLib/SolidModels/LinearElasticIsotropic.h b/MaterialLib/SolidModels/LinearElasticIsotropic.h
index 2bd88582428d34a70668280d0816076ccb72ea17..5e9271dc0192cb4a000497de952495ebbd183ad6 100644
--- a/MaterialLib/SolidModels/LinearElasticIsotropic.h
+++ b/MaterialLib/SolidModels/LinearElasticIsotropic.h
@@ -124,8 +124,8 @@ public:
                                   ProcessLib::SpatialPosition const& x,
                                   double const T) const;
 
+    MaterialProperties getMaterialProperties() const { return _mp; }
 
-    MaterialProperties getMaterialProperties() { return _mp; }
 protected:
     MaterialProperties _mp;
 };