diff --git a/app/interactors/add_group_stage_to_tournament.rb b/app/interactors/add_group_stage_to_tournament.rb
index d8071f2..77956f6 100644
--- a/app/interactors/add_group_stage_to_tournament.rb
+++ b/app/interactors/add_group_stage_to_tournament.rb
@@ -6,7 +6,7 @@ class AddGroupStageToTournament
   def call
     tournament = context.tournament
     groups = context.groups
-    context.fail! if tournament.stages.size > 1
+    context.fail! unless tournament.stages.empty?
     if (group_stage = GroupStageService.generate_group_stage(groups))
       tournament.stages = [group_stage]
       context.tournament = tournament