diff --git a/src/IR/HeuristicSearchPlanEnumerator.cpp b/src/IR/HeuristicSearchPlanEnumerator.cpp
index b24079b1..20d6383f 100644
--- a/src/IR/HeuristicSearchPlanEnumerator.cpp
+++ b/src/IR/HeuristicSearchPlanEnumerator.cpp
@@ -328,11 +328,13 @@ bool heuristic_search_helper(const char *vertex_str, const char *expand_str, con
             if (options::initialize_upper_bound) {
                 config.upper_bound = [&]() {
                     /*----- Run GOO to compute upper bound of plan cost. -----*/
+                    /* Obtain the sum of the costs of the left and the right subplan of the resulting plan. The costs
+                     * considered for the search do not include the cardinality of the result set. */
                     GOO Goo;
                     Goo(G, CF, PT);
-                    auto &plan = PT.get_final();
+                    const auto &plan = PT.get_final();
                     M_insist(not plan.left.empty() and not plan.right.empty());
-                    return plan.cost;
+                    return PT[plan.left].cost + PT[plan.right].cost;
                 }();
             }
         } else if (options::initialize_upper_bound) {
diff --git a/unittest/IR/HeuristicSearchPlanEnumeratorTest.cpp b/unittest/IR/HeuristicSearchPlanEnumeratorTest.cpp
index a69c25c5..c866823a 100644
--- a/unittest/IR/HeuristicSearchPlanEnumeratorTest.cpp
+++ b/unittest/IR/HeuristicSearchPlanEnumeratorTest.cpp
@@ -3400,7 +3400,8 @@ TEST_CASE("AnytimeAStar_BottomUp_and_TopDown_initial_upper_bound", "[core][IR]")
         /*----- Run GOO to compute upper bound of plan cost. -----*/
         GOO Goo;
         Goo(G, C_out, plan_table);
-        return plan_table.get_final().cost;
+        const auto &plan = plan_table.get_final();
+        return plan_table[plan.left].cost + plan_table[plan.right].cost;
     }();
 
 
@@ -3460,19 +3461,19 @@ TEST_CASE("AnytimeAStar_BottomUp_and_TopDown_initial_upper_bound", "[core][IR]")
         CHECK(State::NUM_STATES_GENERATED() == 6);
         CHECK(State::NUM_STATES_EXPANDED() == 1);
         CHECK(State::NUM_STATES_CONSTRUCTED() == 7);
-        CHECK(State::NUM_STATES_DISPOSED() == 1);
+        CHECK(State::NUM_STATES_DISPOSED() == 3);
 
         const auto &SM = S.state_manager();
 
-        CHECK(SM.num_new() == 6);
+        CHECK(SM.num_new() == 4);
         CHECK(SM.num_duplicates() == 0);
         CHECK(SM.num_discarded() == 0);
         CHECK(SM.num_cheaper() == 0);
         CHECK(SM.num_decrease_key() == 0);
-        CHECK(SM.num_pruned_by_cost() == 1);
+        CHECK(SM.num_pruned_by_cost() == 3);
 
-        CHECK(SM.num_states_seen() == 6);
-        CHECK(SM.num_states_in_regular_queue() == 5);
+        CHECK(SM.num_states_seen() == 4);
+        CHECK(SM.num_states_in_regular_queue() == 3);
         CHECK(SM.num_states_in_beam_queue() == 0);
         CHECK(S.num_cached_heuristic_value() == 0);
         CHECK(SM.num_regular_to_beam() == 0);
@@ -3528,19 +3529,19 @@ TEST_CASE("AnytimeAStar_BottomUp_and_TopDown_initial_upper_bound", "[core][IR]")
         CHECK(State::NUM_STATES_GENERATED() == 6);
         CHECK(State::NUM_STATES_EXPANDED() == 1);
         CHECK(State::NUM_STATES_CONSTRUCTED() == 7);
-        CHECK(State::NUM_STATES_DISPOSED() == 1);
+        CHECK(State::NUM_STATES_DISPOSED() == 3);
 
         const auto &SM = S.state_manager();
 
-        CHECK(SM.num_new() == 6);
+        CHECK(SM.num_new() == 4);
         CHECK(SM.num_duplicates() == 0);
         CHECK(SM.num_discarded() == 0);
         CHECK(SM.num_cheaper() == 0);
         CHECK(SM.num_decrease_key() == 0);
-        CHECK(SM.num_pruned_by_cost() == 1);
+        CHECK(SM.num_pruned_by_cost() == 3);
 
-        CHECK(SM.num_states_seen() == 6);
-        CHECK(SM.num_states_in_regular_queue() == 5);
+        CHECK(SM.num_states_seen() == 4);
+        CHECK(SM.num_states_in_regular_queue() == 3);
         CHECK(SM.num_states_in_beam_queue() == 0);
         CHECK(S.num_cached_heuristic_value() == 0);
         CHECK(SM.num_regular_to_beam() == 0);
@@ -3658,21 +3659,21 @@ TEST_CASE("AnytimeAStar_BottomUp_and_TopDown_initial_upper_bound", "[core][IR]")
         CHECK(State::NUM_STATES_GENERATED() == 11);
         CHECK(State::NUM_STATES_EXPANDED() == 4);
         CHECK(State::NUM_STATES_CONSTRUCTED() == 12);
-        CHECK(State::NUM_STATES_DISPOSED() == 3);
+        CHECK(State::NUM_STATES_DISPOSED() == 5);
 
         const auto &SM = S.state_manager();
 
-        CHECK(SM.num_new() == 9);
-        CHECK(SM.num_duplicates() == 1);
-        CHECK(SM.num_discarded() == 1);
+        CHECK(SM.num_new() == 7);
+        CHECK(SM.num_duplicates() == 0);
+        CHECK(SM.num_discarded() == 0);
         CHECK(SM.num_cheaper() == 0);
         CHECK(SM.num_decrease_key() == 0);
-        CHECK(SM.num_pruned_by_cost() == 2);
+        CHECK(SM.num_pruned_by_cost() == 5);
 
-        CHECK(SM.num_states_seen() == 9);
-        CHECK(SM.num_states_in_regular_queue() == 4);
+        CHECK(SM.num_states_seen() == 7);
+        CHECK(SM.num_states_in_regular_queue() == 2);
         CHECK(SM.num_states_in_beam_queue() == 0);
-        CHECK(S.num_cached_heuristic_value() == 1);
+        CHECK(S.num_cached_heuristic_value() == 0);
         CHECK(SM.num_regular_to_beam() == 0);
         CHECK(SM.num_none_to_beam() == 0);
     }