diff --git a/opm/autodiff/BlackoilAmgCpr.hpp b/opm/autodiff/BlackoilAmgCpr.hpp
index d3f61d3933..ae6ece9763 100644
--- a/opm/autodiff/BlackoilAmgCpr.hpp
+++ b/opm/autodiff/BlackoilAmgCpr.hpp
@@ -136,12 +136,10 @@ namespace Opm
         {
         }
 
-        void updatePreconditioner(const typename TwoLevelMethod::FineDomainType& weights,
-                                  const Operator& fineOperator,
+        void updatePreconditioner(const Operator& fineOperator,
                                   const SmootherArgs& smargs,
                                   const Communication& comm)
         {
-            weights_ = weights;
             *scaledMatrix_ = *Detail::scaleMatrixDRS(fineOperator, COMPONENT_INDEX, weights_, param_);
             smoother_.reset(Detail::constructSmoother<Smoother>(*scaledMatrixOperator_, smargs, comm));
             twoLevelMethod_.updatePreconditioner(*scaledMatrixOperator_,
@@ -170,7 +168,7 @@ namespace Opm
 
     private:
         const CPRParameter& param_;
-        typename TwoLevelMethod::FineDomainType weights_; //make copy
+        const typename TwoLevelMethod::FineDomainType& weights_;
         std::unique_ptr<Matrix> scaledMatrix_;
         std::unique_ptr<Operator> scaledMatrixOperator_;
         std::shared_ptr<Smoother> smoother_;
diff --git a/opm/autodiff/ISTLSolverEbosCpr.hpp b/opm/autodiff/ISTLSolverEbosCpr.hpp
index ec38787382..9b38d785ac 100644
--- a/opm/autodiff/ISTLSolverEbosCpr.hpp
+++ b/opm/autodiff/ISTLSolverEbosCpr.hpp
@@ -268,7 +268,7 @@ namespace Opm
 		if(this->parameters_.cpr_solver_verbose_){
 		  std::cout << " Only update amg solver " << std::endl;
 		}
-		amg_->updatePreconditioner(this->weights_,opARef, smootherArgs, comm);
+		amg_->updatePreconditioner(opARef, smootherArgs, comm);
 	      }
 	      // Solve.
 	      //SuperClass::solve(linearOperator, x, istlb, *sp, *amg, result);