diff --git a/app/jobs/reset_expiring_dossiers_job.rb b/app/jobs/reset_expiring_dossiers_job.rb
new file mode 100644
index 000000000..7f4b4d166
--- /dev/null
+++ b/app/jobs/reset_expiring_dossiers_job.rb
@@ -0,0 +1,13 @@
+class ResetExpiringDossiersJob < ApplicationJob
+  def perform(procedure)
+    procedure.dossiers
+      .where.not(brouillon_close_to_expiration_notice_sent_at: nil)
+      .or(Dossier.where.not(en_construction_close_to_expiration_notice_sent_at: nil))
+      .or(Dossier.where.not(termine_close_to_expiration_notice_sent_at: nil))
+      .in_batches do |relation|
+      relation.update_all(brouillon_close_to_expiration_notice_sent_at: nil,
+                          en_construction_close_to_expiration_notice_sent_at: nil,
+                          termine_close_to_expiration_notice_sent_at: nil)
+    end
+  end
+end
diff --git a/app/models/procedure.rb b/app/models/procedure.rb
index f8afa3180..6f077f0dc 100644
--- a/app/models/procedure.rb
+++ b/app/models/procedure.rb
@@ -312,6 +312,8 @@ class Procedure < ApplicationRecord
   validate :validate_auto_archive_on_in_the_future, if: :will_save_change_to_auto_archive_on?
 
   before_save :update_juridique_required
+  after_save :extend_conservation_for_dossiers
+
   after_initialize :ensure_path_exists
   before_save :ensure_path_exists
   after_create :ensure_defaut_groupe_instructeur
@@ -904,6 +906,15 @@ class Procedure < ApplicationRecord
     end
   end
 
+  def extend_conservation_for_dossiers
+    return if previous_changes.include?(:duree_conservation_dossiers_dans_ds)
+    before, after = duree_conservation_dossiers_dans_ds_previous_change
+    return if [before, after].any?(&:nil?)
+    return if (after - before).negative?
+
+    ResetExpiringDossiersJob.perform_later(self)
+  end
+
   def ensure_defaut_groupe_instructeur
     if self.groupe_instructeurs.empty?
       gi = groupe_instructeurs.create(label: GroupeInstructeur::DEFAUT_LABEL)
diff --git a/spec/jobs/reset_expiring_dossiers_job_spec.rb b/spec/jobs/reset_expiring_dossiers_job_spec.rb
new file mode 100644
index 000000000..f61fab25f
--- /dev/null
+++ b/spec/jobs/reset_expiring_dossiers_job_spec.rb
@@ -0,0 +1,19 @@
+describe ResetExpiringDossiersJob do
+  subject { described_class.new(procedure).perform_now }
+  let(:duree_conservation_dossiers_dans_ds) { 2 }
+  let(:procedure) { create(:procedure, duree_conservation_dossiers_dans_ds:) }
+
+  describe '.perform_now' do
+    it 'resets flags' do
+      expiring_dossier_brouillon = create(:dossier, :brouillon, procedure: procedure, brouillon_close_to_expiration_notice_sent_at: duree_conservation_dossiers_dans_ds.months.ago)
+      expiring_dossier_en_construction = create(:dossier, :en_construction, procedure: procedure, en_construction_close_to_expiration_notice_sent_at: duree_conservation_dossiers_dans_ds.months.ago)
+      expiring_dossier_en_termine = create(:dossier, :accepte, procedure: procedure, termine_close_to_expiration_notice_sent_at: duree_conservation_dossiers_dans_ds.months.ago)
+
+      subject
+
+      expect(expiring_dossier_brouillon.reload.brouillon_close_to_expiration_notice_sent_at).to eq(nil)
+      expect(expiring_dossier_en_construction.reload.en_construction_close_to_expiration_notice_sent_at).to eq(nil)
+      expect(expiring_dossier_en_termine.reload.termine_close_to_expiration_notice_sent_at).to eq(nil)
+    end
+  end
+end
diff --git a/spec/models/procedure_spec.rb b/spec/models/procedure_spec.rb
index 4d7583e3b..516d54eda 100644
--- a/spec/models/procedure_spec.rb
+++ b/spec/models/procedure_spec.rb
@@ -1656,6 +1656,43 @@ describe Procedure do
     end
   end
 
+  describe 'extend_conservation_for_dossiers' do
+    let(:duree_conservation_dossiers_dans_ds) { 2 }
+    let(:procedure) { create(:procedure, duree_conservation_dossiers_dans_ds:) }
+    let(:expiring_dossier_brouillon) { create(:dossier, :brouillon, procedure: procedure, brouillon_close_to_expiration_notice_sent_at: duree_conservation_dossiers_dans_ds.months.ago) }
+    let(:expiring_dossier_en_construction) { create(:dossier, :en_construction, procedure: procedure, en_construction_close_to_expiration_notice_sent_at: duree_conservation_dossiers_dans_ds.months.ago) }
+    let(:expiring_dossier_en_termine) { create(:dossier, :accepte, procedure: procedure, termine_close_to_expiration_notice_sent_at: duree_conservation_dossiers_dans_ds.months.ago) }
+    let(:not_expiring_dossie) { create(:dossier, :accepte, procedure: procedure, created_at: duree_conservation_dossiers_dans_ds.months.ago) }
+    before do
+      procedure
+      expiring_dossier_brouillon
+      expiring_dossier_en_construction
+      expiring_dossier_en_termine
+      not_expiring_dossie
+    end
+
+    context 'when duree_conservation_dossiers_dans_ds does not changes' do
+      it 'does not enqueues any job' do
+        expect(ResetExpiringDossiersJob).not_to receive(:perform_later)
+        procedure.update!(libelle: 'does not change duree_conservation_dossiers_dans_ds')
+      end
+    end
+
+    context 'when duree_conservation_dossiers_dans_ds decreases' do
+      it 'calls extend_conservation_for_dossiers' do
+        expect(ResetExpiringDossiersJob).not_to receive(:perform_later)
+        procedure.update(duree_conservation_dossiers_dans_ds: duree_conservation_dossiers_dans_ds - 1)
+      end
+    end
+
+    context 'when duree_conservation_dossiers_dans_ds increases' do
+      it 'calls extend_conservation_for_dossiers' do
+        expect(ResetExpiringDossiersJob).not_to receive(:perform_later)
+        procedure.update(duree_conservation_dossiers_dans_ds: duree_conservation_dossiers_dans_ds + 1)
+      end
+    end
+  end
+
   private
 
   def create_dossier_with_pj_of_size(size, procedure)