diff --git a/app/controllers/champs/carte_controller.rb b/app/controllers/champs/carte_controller.rb
index eb799ea92..5374c5111 100644
--- a/app/controllers/champs/carte_controller.rb
+++ b/app/controllers/champs/carte_controller.rb
@@ -74,5 +74,9 @@ class Champs::CarteController < ApplicationController
     if @champ.persisted?
       @champ.save
     end
+
+  rescue RestClient::ResourceNotFound
+    flash.alert = 'Les données cartographiques sont temporairement indisponibles. Réessayez dans un instant.'
+    response.status = 503
   end
 end
diff --git a/app/lib/api_carto/api.rb b/app/lib/api_carto/api.rb
index 80cadb1b0..651cc97eb 100644
--- a/app/lib/api_carto/api.rb
+++ b/app/lib/api_carto/api.rb
@@ -13,10 +13,10 @@ class ApiCarto::API
 
   def self.call(url, geojson)
     params = geojson.to_s
-
     RestClient.post(url, params, content_type: 'application/json')
 
-  rescue RestClient::InternalServerError
+  rescue RestClient::InternalServerError => e
+    Rails.logger.error "[ApiCarto] Error on #{url}: #{e}"
     raise RestClient::ResourceNotFound
   end
 end
diff --git a/app/views/champs/carte/show.js.erb b/app/views/champs/carte/show.js.erb
index 45ae01b28..e5c1e7055 100644
--- a/app/views/champs/carte/show.js.erb
+++ b/app/views/champs/carte/show.js.erb
@@ -1,3 +1,5 @@
+<%= render_flash(timeout: 5000, fixed: true) %>
+
 <%= render_to_element("#{@selector} + .geo-areas",
   partial: 'shared/champs/carte/geo_areas',
   locals: { champ: @champ, error: @error }) %>
diff --git a/spec/controllers/champs/carte_controller_spec.rb b/spec/controllers/champs/carte_controller_spec.rb
index a530593eb..374574e09 100644
--- a/spec/controllers/champs/carte_controller_spec.rb
+++ b/spec/controllers/champs/carte_controller_spec.rb
@@ -25,43 +25,65 @@ describe Champs::CarteController, type: :controller do
   describe 'POST #show' do
     render_views
 
-    before { sign_in user }
-    before do
-      allow_any_instance_of(ApiCarto::QuartiersPrioritairesAdapter)
-        .to receive(:results)
-        .and_return([{ code: "QPCODE1234", geometry: { type: "MultiPolygon", coordinates: [[[[2.38715792094576, 48.8723062632126], [2.38724851642619, 48.8721392348061]]]] } }])
+    context 'when the API is available' do
+      render_views
 
-      post :show, params: params, format: 'js'
+      before do
+        sign_in user
+
+        allow_any_instance_of(ApiCarto::QuartiersPrioritairesAdapter)
+          .to receive(:results)
+          .and_return([{ code: "QPCODE1234", geometry: { type: "MultiPolygon", coordinates: [[[[2.38715792094576, 48.8723062632126], [2.38724851642619, 48.8721392348061]]]] } }])
+
+        post :show, params: params, format: 'js'
+      end
+
+      context 'when coordinates are empty' do
+        let(:value) { '[]' }
+
+        it {
+          expect(assigns(:error)).to eq(nil)
+          expect(champ.reload.value).to eq(nil)
+          expect(champ.reload.geo_areas).to eq([])
+          expect(response.body).to include("DS.drawMapData(\".carte-1\", {\"position\":{\"lon\":\"2.428462\",\"lat\":\"46.538192\",\"zoom\":\"13\"},\"selection\":null,\"quartiersPrioritaires\":[],\"cadastres\":[],\"parcellesAgricoles\":[]});")
+        }
+      end
+
+      context 'when coordinates are informed' do
+        let(:value) { [[{ "lat": 48.87442541960633, "lng": 2.3859214782714844 }, { "lat": 48.87273183590832, "lng": 2.3850631713867183 }, { "lat": 48.87081237174292, "lng": 2.3809432983398438 }, { "lat": 48.8712640169951, "lng": 2.377510070800781 }, { "lat": 48.87510283703279, "lng": 2.3778533935546875 }, { "lat": 48.87544154230615, "lng": 2.382831573486328 }, { "lat": 48.87442541960633, "lng": 2.3859214782714844 }]].to_json }
+
+        it { expect(response.body).not_to be_nil }
+        it { expect(response.body).to include('MultiPolygon') }
+        it { expect(response.body).to include('[2.38715792094576,48.8723062632126]') }
+      end
+
+      context 'when error' do
+        let(:geojson) { [[{ "lat": 48.87442541960633, "lng": 2.3859214782714844 }, { "lat": 48.87273183590832, "lng": 2.3850631713867183 }, { "lat": 48.87081237174292, "lng": 2.3809432983398438 }, { "lat": 48.8712640169951, "lng": 2.377510070800781 }, { "lat": 48.87510283703279, "lng": 2.3778533935546875 }, { "lat": 48.87544154230615, "lng": 2.382831573486328 }, { "lat": 48.87442541960633, "lng": 2.3859214782714844 }]] }
+        let(:value) { '' }
+
+        it {
+          expect(assigns(:error)).to eq(true)
+          expect(champ.reload.value).to eq(nil)
+          expect(champ.reload.geo_areas).to eq([])
+        }
+      end
     end
 
-    context 'when coordinates are empty' do
-      let(:value) { '[]' }
+    context 'when the API is unavailable' do
+      before do
+        sign_in user
 
-      it {
-        expect(assigns(:error)).to eq(nil)
-        expect(champ.reload.value).to eq(nil)
-        expect(champ.reload.geo_areas).to eq([])
-        expect(response.body).to include("DS.drawMapData(\".carte-1\", {\"position\":{\"lon\":\"2.428462\",\"lat\":\"46.538192\",\"zoom\":\"13\"},\"selection\":null,\"quartiersPrioritaires\":[],\"cadastres\":[],\"parcellesAgricoles\":[]});")
-      }
-    end
+        allow_any_instance_of(ApiCarto::QuartiersPrioritairesAdapter)
+          .to receive(:results)
+          .and_raise(RestClient::ResourceNotFound)
+
+        post :show, params: params, format: 'js'
+      end
 
-    context 'when coordinates are informed' do
       let(:value) { [[{ "lat": 48.87442541960633, "lng": 2.3859214782714844 }, { "lat": 48.87273183590832, "lng": 2.3850631713867183 }, { "lat": 48.87081237174292, "lng": 2.3809432983398438 }, { "lat": 48.8712640169951, "lng": 2.377510070800781 }, { "lat": 48.87510283703279, "lng": 2.3778533935546875 }, { "lat": 48.87544154230615, "lng": 2.382831573486328 }, { "lat": 48.87442541960633, "lng": 2.3859214782714844 }]].to_json }
 
-      it { expect(response.body).not_to be_nil }
-      it { expect(response.body).to include('MultiPolygon') }
-      it { expect(response.body).to include('[2.38715792094576,48.8723062632126]') }
-    end
-
-    context 'when error' do
-      let(:geojson) { [[{ "lat": 48.87442541960633, "lng": 2.3859214782714844 }, { "lat": 48.87273183590832, "lng": 2.3850631713867183 }, { "lat": 48.87081237174292, "lng": 2.3809432983398438 }, { "lat": 48.8712640169951, "lng": 2.377510070800781 }, { "lat": 48.87510283703279, "lng": 2.3778533935546875 }, { "lat": 48.87544154230615, "lng": 2.382831573486328 }, { "lat": 48.87442541960633, "lng": 2.3859214782714844 }]] }
-      let(:value) { '' }
-
-      it {
-        expect(assigns(:error)).to eq(true)
-        expect(champ.reload.value).to eq(nil)
-        expect(champ.reload.geo_areas).to eq([])
-      }
+      it { expect(response.status).to eq 503 }
+      it { expect(response.body).to include('Les données cartographiques sont temporairement indisponibles') }
     end
   end
 end