diff --git a/app/models/concerns/dossier_sections_concern.rb b/app/models/concerns/dossier_sections_concern.rb
index bd8166efe..57ddf0ccf 100644
--- a/app/models/concerns/dossier_sections_concern.rb
+++ b/app/models/concerns/dossier_sections_concern.rb
@@ -22,14 +22,19 @@ module DossierSectionsConcern
 
     def index_for_section_header(champ)
       champs = champ.private? ? champs_private : champs_public
-
       index = 1
       champs.each do |c|
-        return index if c.stable_id == champ.stable_id
-        next unless c.visible?
+        if c.repetition?
+          index_in_repetition = c.rows.flatten.filter { _1.stable_id == champ.stable_id }.find_index(champ)
+          return "#{index}.#{index_in_repetition + 1}" if index_in_repetition
+        else
+          return index if c.stable_id == champ.stable_id
+          next unless c.visible?
 
-        index += 1 if c.type_de_champ.header_section?
+          index += 1 if c.type_de_champ.header_section?
+        end
       end
+      index
     end
   end
 end
diff --git a/spec/models/dossier_spec.rb b/spec/models/dossier_spec.rb
index 5dc4d8f28..7d18d0301 100644
--- a/spec/models/dossier_spec.rb
+++ b/spec/models/dossier_spec.rb
@@ -1317,6 +1317,18 @@ describe Dossier do
     end
   end
 
+  describe 'index_for_section_header' do
+    let(:procedure) { create(:procedure, types_de_champ_public: types_de_champ) }
+    let(:dossier) { create(:dossier, procedure: procedure) }
+    let(:types_de_champ) { [{ type: :repetition, mandatory: true, children: [{ type: :header_section }] }] }
+
+    it 'index classly' do
+      repetition = dossier.champs.find(&:repetition?)
+      header_in_repetition = repetition.champs.find(&:header_section?)
+      expect(dossier.index_for_section_header(header_in_repetition)).to eq("1.1")
+    end
+  end
+
   describe '#repasser_en_instruction!' do
     let(:dossier) { create(:dossier, :refuse, :with_attestation, archived: true, termine_close_to_expiration_notice_sent_at: Time.zone.now) }
     let!(:instructeur) { create(:instructeur) }