diff --git a/app/models/dossier.rb b/app/models/dossier.rb
index 3956c14f9..0e8aee571 100644
--- a/app/models/dossier.rb
+++ b/app/models/dossier.rb
@@ -124,7 +124,7 @@ class Dossier < ApplicationRecord
   has_many :types_de_champ, through: :revision
   has_many :types_de_champ_private, through: :revision
 
-  belongs_to :transfer, class_name: 'DossierTransfer', foreign_key: 'dossier_transfer_id', optional: true, inverse_of: :dossiers, dependent: :destroy
+  belongs_to :transfer, class_name: 'DossierTransfer', foreign_key: 'dossier_transfer_id', optional: true, inverse_of: :dossiers
   has_many :transfer_logs, class_name: 'DossierTransferLog', dependent: :destroy
 
   accepts_nested_attributes_for :champs
diff --git a/lib/tasks/deployment/20211006154552_remove_orphaned_avis.rake b/lib/tasks/deployment/20211006154552_remove_orphaned_avis.rake
new file mode 100644
index 000000000..f782cf6b1
--- /dev/null
+++ b/lib/tasks/deployment/20211006154552_remove_orphaned_avis.rake
@@ -0,0 +1,22 @@
+namespace :after_party do
+  desc 'Deployment task: remove_orphaned_avis'
+  task remove_orphaned_avis: :environment do
+    puts "Running deploy task 'remove_orphaned_avis'"
+
+    avis = Avis.unscope(:joins)
+      .joins('LEFT JOIN dossiers ON dossiers.id = avis.dossier_id')
+      .where(dossiers: { id: nil })
+    progress = ProgressReport.new(avis.count)
+
+    avis.find_each do |avis|
+      avis.destroy
+      progress.inc
+    end
+    progress.finish
+
+    # Update task as completed.  If you remove the line below, the task will
+    # run with every deploy (or every time you call after_party:run).
+    AfterParty::TaskRecord
+      .create version: AfterParty::TaskRecorder.new(__FILE__).timestamp
+  end
+end
diff --git a/spec/factories/dossier_transfer.rb b/spec/factories/dossier_transfer.rb
new file mode 100644
index 000000000..fef311665
--- /dev/null
+++ b/spec/factories/dossier_transfer.rb
@@ -0,0 +1,5 @@
+FactoryBot.define do
+  factory :dossier_transfer do
+    email { generate(:user_email) }
+  end
+end
diff --git a/spec/models/dossier_spec.rb b/spec/models/dossier_spec.rb
index 8886cc206..df75ca854 100644
--- a/spec/models/dossier_spec.rb
+++ b/spec/models/dossier_spec.rb
@@ -1439,14 +1439,18 @@ describe Dossier do
   end
 
   describe "#destroy" do
-    let(:dossier) { create(:dossier) }
+    let(:transfer) { create(:dossier_transfer) }
+    let(:dossier) { create(:dossier, transfer: transfer) }
+
     before do
+      create(:dossier, transfer: transfer)
       create(:attestation, dossier: dossier)
       create(:attestation, dossier: dossier)
     end
 
     it "can destroy dossier with two attestations" do
       expect(dossier.destroy).to be_truthy
+      expect(transfer.reload).not_to be_nil
     end
   end
 
diff --git a/spec/models/dossier_transfer_spec.rb b/spec/models/dossier_transfer_spec.rb
index 161b03b11..a834b6a26 100644
--- a/spec/models/dossier_transfer_spec.rb
+++ b/spec/models/dossier_transfer_spec.rb
@@ -46,5 +46,16 @@ RSpec.describe DossierTransfer, type: :model do
         it { expect(DossierTransfer.with_dossiers.count).to eq(0) }
       end
     end
+
+    describe 'dossier relationship' do
+      let(:transfer) { create(:dossier_transfer) }
+      let(:dossier) { create(:dossier, user: user, transfer: transfer) }
+
+      it 'nullify transfer relationship on dossier' do
+        expect(dossier.transfer).to eq(transfer)
+        transfer.destroy
+        expect(dossier.reload.transfer).to be_nil
+      end
+    end
   end
 end