diff --git a/spec/controllers/tournaments_controller_spec.rb b/spec/controllers/tournaments_controller_spec.rb
index 43d43bf..1663157 100644
--- a/spec/controllers/tournaments_controller_spec.rb
+++ b/spec/controllers/tournaments_controller_spec.rb
@@ -123,10 +123,18 @@ RSpec.describe TournamentsController, type: :controller do
       end
 
       it 'includes advancing teams' do
+        # mock GroupStageService.get_advancing_teams(@group_stage_tournament.group_stage) to include 4 teams
+        expected_advancing_teams = create_list(:team, 4)
+        allow(GroupStageService).to receive(:get_advancing_teams).and_return(expected_advancing_teams)
+
         get :show, params: { id: @group_stage_tournament.to_param }
         body = deserialize_response response
         advancing_teams = body[:teams_advancing_from_group_stage]
-        expected_advancing_teams = GroupStageService.get_advancing_teams(@group_stage_tournament.group_stage)
+        # check array is not empty
+        expect(advancing_teams).not_to be_empty
+
+        # cast json to teams and compare
+        advancing_teams = advancing_teams.map { |team| Team.find(team[:id]) }
         expect(advancing_teams).to match_array(expected_advancing_teams)
       end
     end
diff --git a/spec/services/group_stage_service_spec.rb b/spec/services/group_stage_service_spec.rb
index 8073ef2..95c800e 100644
--- a/spec/services/group_stage_service_spec.rb
+++ b/spec/services/group_stage_service_spec.rb
@@ -52,6 +52,8 @@ RSpec.describe GroupStageService do
     end
   end
 
+  # TODO test get_advancing_teams when test data for running group stage is ready
+
   describe '#get_group_object_from' do
     it 'returns a group' do
       group = GroupStageService.get_group_object_from(@teams1)