diff --git a/src/opt/opt_params.pyg b/src/opt/opt_params.pyg
index 4235deb3d..dd9e26aae 100644
--- a/src/opt/opt_params.pyg
+++ b/src/opt/opt_params.pyg
@@ -14,7 +14,7 @@ def_module_params('opt',
                           ('elim_01', BOOL, True, 'eliminate 01 variables'),
                           ('pp.neat', BOOL, True, 'use neat (as opposed to less readable, but faster) pretty printer when displaying context'),
                           ('pb.compile_equality', BOOL, False, 'compile arithmetical equalities into pseudo-Boolean equality (instead of two inequalites)'),
-                          ('maxlex.enable', BOOL, False, 'enable maxlex heuristic for lexicographic MaxSAT problems'),
+                          ('maxlex.enable', BOOL, True, 'enable maxlex heuristic for lexicographic MaxSAT problems'),
                           ('maxres.hill_climb', BOOL, True, 'give preference for large weight cores'),
                           ('maxres.add_upper_bound_block', BOOL, False, 'restict upper bound with constraint'),
                           ('maxres.max_num_cores', UINT, UINT_MAX, 'maximal number of cores per round'),