diff --git a/app/services/group_stage_service.rb b/app/services/group_stage_service.rb
index 504ff24..5e92a1d 100644
--- a/app/services/group_stage_service.rb
+++ b/app/services/group_stage_service.rb
@@ -8,7 +8,7 @@ class GroupStageService
       # raise an error if the average group size is not a whole number
       raise 'Groups need to be equal size' unless (groups.flatten.length.to_f / groups.length.to_f % 1).zero?
 
-      groups = groups.map(&method(:get_group_object_from))
+      groups = groups.map(&method(:get_group_object_from)).each_with_index { |group, i| group.number = i + 1 }
       Stage.new level: -1, groups: groups, state: :in_progress
     end
 
diff --git a/spec/services/group_stage_service_spec.rb b/spec/services/group_stage_service_spec.rb
index 2a41658..b5ebf06 100644
--- a/spec/services/group_stage_service_spec.rb
+++ b/spec/services/group_stage_service_spec.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-RSpec.describe GroupStageService, focus: true do
+RSpec.describe GroupStageService do
   before do
     @teams1 = create_list(:team, 4)
     @teams2 = create_list(:team, 4)
@@ -19,6 +19,13 @@ RSpec.describe GroupStageService, focus: true do
       expect(prepared_groups_groupstage.state).to eq('in_progress')
     end
 
+    it 'assigns unique numbers to each group' do
+      groups = prepared_groups_groupstage.groups
+      groups.sort_by(&:number).each_with_index do |group, i|
+        expect(group.number).to eq(i + 1)
+      end
+    end
+
     it 'returns a stage object with level -1' do
       expect(prepared_groups_groupstage.level).to be(-1)
     end