diff --git a/matlab/perfect-foresight-models/perfect_foresight_solver_core.m b/matlab/perfect-foresight-models/perfect_foresight_solver_core.m
index 5e0452892c0aaecc60a9e4bd97746a0af25d410e..4aab19eeb6658274c617baaa6b35ff8b743bd8d5 100644
--- a/matlab/perfect-foresight-models/perfect_foresight_solver_core.m
+++ b/matlab/perfect-foresight-models/perfect_foresight_solver_core.m
@@ -84,7 +84,7 @@ else
                         sim1(oo_.endo_simul, oo_.exo_simul, oo_.steady_state, M_, options_);
                 end
               case 6
-                if option_.linear_approximation
+                if options_.linear_approximation
                     error('Invalid value of stack_solve_algo option!')
                 end
                 [oo_.endo_simul, oo_.deterministic_simulation] = ...