diff --git a/app/services/api_geo_service.rb b/app/services/api_geo_service.rb
index 18e42f451..f2e372bfe 100644
--- a/app/services/api_geo_service.rb
+++ b/app/services/api_geo_service.rb
@@ -123,7 +123,7 @@ class APIGeoService
     end
 
     def safely_normalize_city_name(department_code, city_code, fallback)
-      return fallback if department_code.nil? || city_code.nil?
+      return fallback if department_code.blank? || city_code.blank?
 
       commune_name(department_code, city_code) || fallback
     end
diff --git a/spec/services/api_geo_service_spec.rb b/spec/services/api_geo_service_spec.rb
index 7dda79ec7..00e7a1068 100644
--- a/spec/services/api_geo_service_spec.rb
+++ b/spec/services/api_geo_service_spec.rb
@@ -130,5 +130,17 @@ describe APIGeoService do
 
       it { is_expected.to eq('Paris') }
     end
+
+    context 'with blank department' do
+      let(:department_code) { '' }
+
+      it { is_expected.to eq('Paris') }
+    end
+
+    context 'with blank city_code' do
+      let(:city_code) { '' }
+
+      it { is_expected.to eq('Paris') }
+    end
   end
 end