diff --git a/matlab/discretionary_policy/discretionary_policy_initialization.m b/matlab/discretionary_policy/discretionary_policy_initialization.m
index 197b3bd318cd2bdffd4ed7ceb5b61649957fe8eb..2cdce466fcd9b1f7be84932ca85d5b8fa34cb8f2 100644
--- a/matlab/discretionary_policy/discretionary_policy_initialization.m
+++ b/matlab/discretionary_policy/discretionary_policy_initialization.m
@@ -41,7 +41,7 @@ if isfield(M_,'orig_model')
     M_.maximum_endo_lag = M_.orig_model.maximum_endo_lag;
 end
 
-instr_nbr=M_.orig_endo_nbr-M_.orig_eq_nbr;
+instr_nbr=M_.endo_nbr-M_.eq_nbr;
 
 if instr_nbr==0
     error('discretionary_policy:: There are no available instruments, because the model has as many equations as variables.')