diff --git a/app/models/conference.rb b/app/models/conference.rb
index 01a8d8b4..23572132 100644
--- a/app/models/conference.rb
+++ b/app/models/conference.rb
@@ -41,6 +41,7 @@ class Conference < ActiveRecord::Base
   has_many :difficulty_levels, dependent: :destroy
   has_many :rooms, dependent: :destroy
   has_many :registrations, dependent: :destroy
+  has_many :participants, through: :registrations, source: :user
   has_many :vdays, dependent: :destroy
   has_many :vpositions, dependent: :destroy
   has_many :sponsorship_levels, dependent: :destroy