diff --git a/src/opt/opt_context.cpp b/src/opt/opt_context.cpp
index 4bbbc3865..2f6bad9e8 100644
--- a/src/opt/opt_context.cpp
+++ b/src/opt/opt_context.cpp
@@ -398,10 +398,10 @@ namespace opt {
     
     /**
        \brief there is no need to use push/pop when all objectives are maxsat and engine
-       is maxres or mss.
+       is maxres.
     */
     bool context::scoped_lex() {
-        if (m_maxsat_engine == symbol("maxres") || m_maxsat_engine == symbol("mss")) {
+        if (m_maxsat_engine == symbol("maxres")) {
             for (unsigned i = 0; i < m_objectives.size(); ++i) {
                 if (m_objectives[i].m_type != O_MAXSMT) return true;
             }
diff --git a/src/opt/opt_params.pyg b/src/opt/opt_params.pyg
index e06836f61..41548452a 100644
--- a/src/opt/opt_params.pyg
+++ b/src/opt/opt_params.pyg
@@ -3,7 +3,7 @@ def_module_params('opt',
                   export=True,
                   params=(('optsmt_engine', SYMBOL, 'basic', "select optimization engine: 'basic', 'farkas', 'symba'"),
                           ('maxsat_engine', SYMBOL, 'maxres', "select engine for maxsat: 'core_maxsat', 'wmax', 'maxres', 'pd-maxres', 'mss'"),
-                          ('priority', SYMBOL, 'lex', "select how to prioritize objectives: 'lex' (lexicographic), 'pareto', or 'box'"),
+                          ('priority', SYMBOL, 'lex', "select how to priortize objectives: 'lex' (lexicographic), 'pareto', or 'box'"),
                           ('dump_benchmarks', BOOL, False, 'dump benchmarks for profiling'),
                           ('solution_prefix', SYMBOL, '', "path prefix to dump intermediary, but non-optimal, solutions"),
                           ('timeout', UINT, UINT_MAX, 'timeout (in milliseconds) (UINT_MAX and 0 mean no timeout)'),
diff --git a/src/opt/wmax.cpp b/src/opt/wmax.cpp
index 513c68d6e..52b87e536 100644
--- a/src/opt/wmax.cpp
+++ b/src/opt/wmax.cpp
@@ -84,9 +84,6 @@ namespace opt {
                 if (m.canceled()) {
                     is_sat = l_undef;
                 }
-                if (is_sat == l_undef) {
-                    break;
-                }
                 if (is_sat == l_false) {
                     TRACE("opt", tout << "Unsat\n";);
                     break;
@@ -100,6 +97,9 @@ namespace opt {
                     //DEBUG_CODE(verify_cores(cores););
                     s().assert_expr(fml);
                 }
+                else {
+                    //DEBUG_CODE(verify_cores(cores););
+                }
                 update_cores(wth(), cores);
                 wth().init_min_cost(m_upper - m_lower);
                 trace_bounds("wmax");