diff --git a/src/DynamicModel.cc b/src/DynamicModel.cc
index 49f9dd90d0bd66d632171eb74fc6a3ae25b76d29..9077c5e5aaf238d846dd27e396eb41cabc866483 100644
--- a/src/DynamicModel.cc
+++ b/src/DynamicModel.cc
@@ -599,7 +599,7 @@ DynamicModel::writeModelEquationsOrdered_M(const string &basename) const
       else if (simulation_type == SOLVE_TWO_BOUNDARIES_COMPLETE || simulation_type == SOLVE_TWO_BOUNDARIES_SIMPLE)
         output << "  residual=zeros(" << block_mfs << ",y_kmin+periods);" << endl;
       if (simulation_type == EVALUATE_BACKWARD)
-        output << "  for it_ = (y_kmin+periods):y_kmin+1" << endl;
+        output << "  for it_ = (y_kmin+periods):-1:y_kmin+1" << endl;
       if (simulation_type == EVALUATE_FORWARD)
         output << "  for it_ = y_kmin+1:(y_kmin+periods)" << endl;
 
@@ -2148,7 +2148,7 @@ DynamicModel::writeSparseDynamicMFile(const string &basename) const
                             << "  oo_.deterministic_simulation.block(blck_num).error = 0;" << endl
                             << "  oo_.deterministic_simulation.block(blck_num).iterations = 0;" << endl
                             << "  g1=[];g2=[];g3=[];" << endl
-                            << "  " << basename << ".block.dynamic_" << block + 1 << "(y, x, params, steady_state, 0, y_kmin, periods);" << endl
+                            << "  y = " << basename << ".block.dynamic_" << block + 1 << "(y, x, params, steady_state, 0, y_kmin, periods);" << endl
                             << "  tmp = y(:,M_.block_structure.block(" << block + 1 << ").variable);" << endl
                             << "  if any(isnan(tmp) | isinf(tmp))" << endl
                             << "    disp(['Inf or Nan value during the evaluation of block " << block <<"']);" << endl