diff --git a/matlab/stochastic_solvers.m b/matlab/stochastic_solvers.m
index 4e0448568..cd9a839bd 100644
--- a/matlab/stochastic_solvers.m
+++ b/matlab/stochastic_solvers.m
@@ -216,6 +216,7 @@ if M_.maximum_endo_lead == 0
     % backward models: simplified code exist only at order == 1
     if local_order == 1
         [k1,~,k2] = find(kstate(:,4));
+        dr.state_var = k2;
         dr.ghx(:,k1) = -b\jacobia_(:,k2);
         if M_.exo_nbr
             dr.ghu =  -b\jacobia_(:,nz+1:end);