diff --git a/src/Service/PublicHolidayService.php b/src/Service/PublicHolidayService.php
index da2b49b..75dbb69 100644
--- a/src/Service/PublicHolidayService.php
+++ b/src/Service/PublicHolidayService.php
@@ -15,6 +15,8 @@ use Throwable;
 
 final class PublicHolidayService implements PublicHolidayServiceInterface
 {
+    private const string BASE_URL = 'https://calendrier.api.gouv.fr/jours-feries/';
+
     public function __construct(
         private readonly HttpClientInterface $client,
     ) {}
@@ -29,7 +31,7 @@ final class PublicHolidayService implements PublicHolidayServiceInterface
     public function getHolidaysDay(string $zone): array
     {
         $zone = strtolower(trim($zone));
-        $url  = "https://calendrier.api.gouv.fr/jours-feries/{$zone}.json";
+        $url  = self::BASE_URL."{$zone}.json";
 
         try {
             $response = $this->client->request(
@@ -59,7 +61,7 @@ final class PublicHolidayService implements PublicHolidayServiceInterface
     {
         $zone  = strtolower(trim($zone));
         $years = trim($years);
-        $url   = "https://calendrier.api.gouv.fr/jours-feries/{$zone}/{$years}.json";
+        $url   = self::BASE_URL."{$zone}/{$years}.json";
 
         try {
             $response = $this->client->request('GET', $url);