diff --git a/app/models/user_geometry.rb b/app/models/user_geometry.rb
index 8f5e398aa..74633bc8d 100644
--- a/app/models/user_geometry.rb
+++ b/app/models/user_geometry.rb
@@ -5,7 +5,7 @@ class UserGeometry
     @json_latlngs = json_latlngs
   end
 
-  def value
+  def geometry
     to_geo_json(@json_latlngs)
   end
 
diff --git a/app/serializers/cadastre_serializer.rb b/app/serializers/cadastre_serializer.rb
deleted file mode 100644
index 193a292a5..000000000
--- a/app/serializers/cadastre_serializer.rb
+++ /dev/null
@@ -1,17 +0,0 @@
-class CadastreSerializer < ActiveModel::Serializer
-  attributes :value, :type_de_champ
-
-  def value
-    object.geometry
-  end
-
-  def type_de_champ
-    {
-      id: -1,
-      libelle: 'cadastre',
-      type_champ: 'cadastre',
-      order_place: -1,
-      descripton: ''
-    }
-  end
-end
diff --git a/app/serializers/champ_serializer.rb b/app/serializers/champ_serializer.rb
index 454d3b944..c57c185f9 100644
--- a/app/serializers/champ_serializer.rb
+++ b/app/serializers/champ_serializer.rb
@@ -6,10 +6,62 @@ class ChampSerializer < ActiveModel::Serializer
   has_one :type_de_champ
 
   def value
-    if object.piece_justificative_file.attached?
-      url_for(object.piece_justificative_file)
+    case object
+    when GeoArea, UserGeometry, Cadastre, QuartierPrioritaire
+      object.geometry
     else
-      object.value
+      if object.piece_justificative_file.attached?
+        url_for(object.piece_justificative_file)
+      else
+        object.value
+      end
+    end
+  end
+
+  def type_de_champ
+    case object
+    when GeoArea, UserGeometry, Cadastre, QuartierPrioritaire
+      legacy_type_de_champ
+    else
+      object.type_de_champ
+    end
+  end
+
+  private
+
+  def legacy_type_de_champ
+    {
+      id: -1,
+      libelle: legacy_carto_libelle,
+      type_champ: legacy_carto_type_champ,
+      order_place: -1,
+      descripton: ''
+    }
+  end
+
+  def legacy_carto_libelle
+    case object
+    when UserGeometry, Cadastre, QuartierPrioritaire
+      object.class.name.underscore.tr('_', ' ')
+    else
+      if object.source == GeoArea.sources.fetch(:selection_utilisateur)
+        'user geometry'
+      else
+        object.source.to_s.tr('_', ' ')
+      end
+    end
+  end
+
+  def legacy_carto_type_champ
+    case object
+    when UserGeometry, Cadastre, QuartierPrioritaire
+      object.class.name.underscore
+    else
+      if object.source == GeoArea.sources.fetch(:selection_utilisateur)
+        'user_geometry'
+      else
+        object.source.to_s
+      end
     end
   end
 end
diff --git a/app/serializers/dossier_serializer.rb b/app/serializers/dossier_serializer.rb
index 75f40effb..851cf7f62 100644
--- a/app/serializers/dossier_serializer.rb
+++ b/app/serializers/dossier_serializer.rb
@@ -23,7 +23,7 @@ class DossierSerializer < ActiveModel::Serializer
   has_many :pieces_justificatives
   has_many :types_de_piece_justificative
 
-  has_many :champs
+  has_many :champs, serializer: ChampSerializer
 
   def champs
     champs = object.champs.to_a
@@ -35,6 +35,16 @@ class DossierSerializer < ActiveModel::Serializer
       if object.user_geometry.present?
         champs << object.user_geometry
       end
+    elsif object.expose_legacy_carto_api?
+      champ_carte = champs.find do |champ|
+        champ.type_de_champ.type_champ == TypeDeChamp.type_champs.fetch(:carte)
+      end
+
+      if champ_carte.present?
+        carto_champs = champ_carte.geo_areas.to_a
+        carto_champs << champ_carte.user_geo_area
+        champs += carto_champs.compact
+      end
     end
 
     champs
diff --git a/app/serializers/quartier_prioritaire_serializer.rb b/app/serializers/quartier_prioritaire_serializer.rb
deleted file mode 100644
index 0c5c73259..000000000
--- a/app/serializers/quartier_prioritaire_serializer.rb
+++ /dev/null
@@ -1,17 +0,0 @@
-class QuartierPrioritaireSerializer < ActiveModel::Serializer
-  attributes :value, :type_de_champ
-
-  def value
-    object.geometry
-  end
-
-  def type_de_champ
-    {
-      id: -1,
-      libelle: 'quartier prioritaire',
-      type_champ: 'quartier_prioritaire',
-      order_place: -1,
-      descripton: ''
-    }
-  end
-end
diff --git a/app/serializers/user_geometry_serializer.rb b/app/serializers/user_geometry_serializer.rb
deleted file mode 100644
index 964bda894..000000000
--- a/app/serializers/user_geometry_serializer.rb
+++ /dev/null
@@ -1,3 +0,0 @@
-class UserGeometrySerializer < ActiveModel::Serializer
-  attributes :value, :type_de_champ
-end
diff --git a/spec/controllers/api/v1/dossiers_controller_spec.rb b/spec/controllers/api/v1/dossiers_controller_spec.rb
index 2cd99a95f..d5566f0f2 100644
--- a/spec/controllers/api/v1/dossiers_controller_spec.rb
+++ b/spec/controllers/api/v1/dossiers_controller_spec.rb
@@ -290,8 +290,8 @@ describe API::V1::DossiersController do
               super().find { |champ| champ[:type_de_champ][:type_champ] == 'user_geometry' }
             end
 
-            it { expect(subject[:type_de_champ]).to match({ id: -1, libelle: 'user_geometry', type_champ: 'user_geometry', order_place: -1, descripton: '' }) }
-            it { expect(subject[:value]).to match(UserGeometry.new(dossier.json_latlngs).value) }
+            it { expect(subject[:type_de_champ]).to match({ id: -1, libelle: 'user geometry', type_champ: 'user_geometry', order_place: -1, descripton: '' }) }
+            it { expect(subject[:value]).to match(UserGeometry.new(dossier.json_latlngs).geometry) }
           end
         end
 
diff --git a/spec/models/dossier_spec.rb b/spec/models/dossier_spec.rb
index 0562d528f..e923aca40 100644
--- a/spec/models/dossier_spec.rb
+++ b/spec/models/dossier_spec.rb
@@ -841,7 +841,7 @@ describe Dossier do
         }
       end
 
-      subject{ dossier.user_geometry.value }
+      subject{ dossier.user_geometry.geometry }
 
       it { is_expected.to eq(expected) }
     end