diff --git a/src/Client.php b/src/Client.php
index cfe596f..ffd2eea 100644
--- a/src/Client.php
+++ b/src/Client.php
@@ -52,7 +52,7 @@ public function getCommunesByDepartementCode(string $departementCode): array
                     coordinates: $commune['centre']['coordinates'],
                 ),
                 surface: $commune['surface'],
-                population: $commune['population'],
+                population: $commune['population'] ?? 0,
                 departement: new CommuneDepartement(
                     nom: $commune['departement']['nom'],
                     code: $commune['departement']['code'],
diff --git a/tests/GeoGouvTest.php b/tests/GeoGouvTest.php
index 614c3dc..f7bebcc 100644
--- a/tests/GeoGouvTest.php
+++ b/tests/GeoGouvTest.php
@@ -30,9 +30,11 @@ public function testGetCommunesByDepartementCode(): void
     {
         $client = new Client();
 
-        $communes = $client->getCommunesByDepartementCode('01');
+        foreach ($client->getDepartements() as $departement) {
+            $communes = $client->getCommunesByDepartementCode($departement->code);
 
-        self::assertIsArray($communes);
-        self::assertInstanceOf(Commune::class, $communes[0]);
+            self::assertIsArray($communes);
+            self::assertInstanceOf(Commune::class, $communes[0]);
+        }
     }
 }