diff --git a/matlab/perfect-foresight-models/sim1_purely_backward.m b/matlab/perfect-foresight-models/sim1_purely_backward.m
index b3d88a7123674ba40893e0f2fe615cd7dfd55f0d..689d4f310d8e490eaca3bf48d5e195a92c1cd9db 100644
--- a/matlab/perfect-foresight-models/sim1_purely_backward.m
+++ b/matlab/perfect-foresight-models/sim1_purely_backward.m
@@ -38,13 +38,13 @@ dynamicmodel = str2func([M.fname,'.dynamic']);
 
 info.status = 1;
 
-for it = 2:options.periods+1
+for it = M.maximum_lag + (1:options.periods)
     yb = endogenousvariables(:,it-1);        % Values at previous period, also used as guess value for current period
     yb1 = yb(iyb);
     [tmp, check] = solve1(dynamicmodel, [yb1; yb], 1:M.endo_nbr, nyb+1:nyb+M.endo_nbr, ...
                           1, options.gstep, options.dynatol.f, options.dynatol.x, ...
                           options.simul.maxit, options.debug, exogenousvariables, ...
-                          M.params, steadystate, it+M.maximum_lag-1);
+                          M.params, steadystate, it);
     if check
         info.status = 0;
     end