diff --git a/matlab/+var_expectation/update_parameters.m b/matlab/+var_expectation/update_parameters.m
index 7b5b08fef9158453de0c343550a36988f0acd92f..f6f638b805c6cbc9f1ddc0c93d9531e1e36f415f 100644
--- a/matlab/+var_expectation/update_parameters.m
+++ b/matlab/+var_expectation/update_parameters.m
@@ -108,6 +108,10 @@ for i = 1:m
     end
 end
 
+if isfield(auxmodel, 'isconstant') && auxmodel.isconstant
+    variables_id_in_var = variables_id_in_var+1;
+end
+
 % Get the horizon parameter.
 horizon = varexpectationmodel.horizon;
 
@@ -214,4 +218,4 @@ if isequal(varexpectationmodel.auxiliary_model_type, 'var')
     end
 else
     DynareModel.params(varexpectationmodel.param_indices) = parameters;
-end
+end
\ No newline at end of file