diff --git a/app/models/event.rb b/app/models/event.rb
index 5edc660..26f1957 100644
--- a/app/models/event.rb
+++ b/app/models/event.rb
@@ -4,7 +4,7 @@ class Event < ActiveRecord::Base
   belongs_to :conference
   belongs_to :track
 
-  has_many :participations
+  has_many :participations, dependent: :destroy
   has_many :pending_participations, ->() { pending }, class_name: 'Participation'
   has_many :approved_participations, ->() { approved }, class_name: 'Participation'
   has_many :participants, through: :approved_participations