diff --git a/app/models/education/diploma.rb b/app/models/education/diploma.rb
index dc0913ddd905e2dedf1396c3abc34f33fc27733a..8b2c7b9ef910b57659d92798078bff6bb64c7329 100644
--- a/app/models/education/diploma.rb
+++ b/app/models/education/diploma.rb
@@ -24,7 +24,7 @@ class Education::Diploma < ApplicationRecord
   include WithGit
   include WithSlug
 
-  has_many :programs
+  has_many :programs, dependent: :nullify
 
   scope :ordered, -> { order(:level, :name) }