diff --git a/src/meta_schedule/search_strategy/evolutionary_search.cc b/src/meta_schedule/search_strategy/evolutionary_search.cc
index cffe1187caeb2..caf39708891c6 100644
--- a/src/meta_schedule/search_strategy/evolutionary_search.cc
+++ b/src/meta_schedule/search_strategy/evolutionary_search.cc
@@ -716,8 +716,7 @@ class EvolutionarySearch : public SearchStrategy {
                                                     EvolutionarySearchNode);
 };
 
-Array<Schedule> EvolutionarySearchSampleInitPopulation(ObjectRef _self, int num) {
-  const EvolutionarySearchNode* self = _self.as<EvolutionarySearchNode>();
+Array<Schedule> EvolutionarySearchSampleInitPopulation(EvolutionarySearch self, int num) {
   std::vector<Schedule> results = self->state_->SampleInitPopulation(num);
   return Array<Schedule>(results.begin(), results.end());
 }
@@ -733,6 +732,7 @@ Array<Schedule> EvolutionarySearchEvolveWithCostModel(ObjectRef _self, Array<Sch
     IRModule mod = sch->mod();
     size_t shash = StructuralHash()(mod);
     if (!self->state_->measured_workloads_.Has(mod, shash)) {
+      self->state_->measured_workloads_.Add(mod, shash);
       result.push_back(sch);
     }
   }