         if( p.nu_parallel !=0)
         {
                 if (p.pollim==1) dzDIR_.set_boundaries( dg::DIR, 0, 0);    
+                #ifndef MPI_VERSION
                 if (p.pardiss==0)
                 {
                     dzDIR_.forward(y[i+2], omega); 

        //Parallel dissipation
        if( p.nu_parallel != 0)
        {
                if (p.pardiss==0)
                {
                    if (p.pollim==1) dzN_.set_boundaries( p.bc, 0, 0);

                    dzDIR_.backwardT(omega,lambda);
                    dg::blas1::axpby( 0.5*p.nu_parallel, lambda, 1., yp[i+2]); 
                }
                #endif
                if (p.pardiss==1)
                {
                    if (p.pollim==1) dzN_.set_boundaries( p.bc, 0, 0);
