diff --git a/src/Service/Geocoder.php b/src/Service/Geocoder.php
index 72e4ec9..b3ec623 100644
--- a/src/Service/Geocoder.php
+++ b/src/Service/Geocoder.php
@@ -10,7 +10,7 @@ use Symfony\Contracts\HttpClient\ResponseInterface;
 
 class Geocoder
 {
-    private const API_URL = "https://nominatim.openstreetmap.org/search";
+    private const string API_URL = "https://nominatim.openstreetmap.org/search";
 
     public function __construct(private HttpClientInterface $client) {}
 
diff --git a/tests/Service/GeocodeTest.php b/tests/Service/GeocodeTest.php
index 4662f23..073f0b8 100644
--- a/tests/Service/GeocodeTest.php
+++ b/tests/Service/GeocodeTest.php
@@ -12,12 +12,12 @@ use Pcm\GeocodeBundle\Tests\AppKernel;
 use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
 
 /**
- * Note we sleep 1s after requests to prevent breaking the API T&Cs
+ * We sleep 1 second after API calls to prevent breaking the API T&Cs.
  */
 class GeocodeTest extends KernelTestCase
 {
     // Buckingham Palace
-    private const POSTCODE = 'SW1A 1AA';
+    private const string POSTCODE = 'SW1A 1AA';
 
     private Geocoder $geocoder;
 
@@ -54,3 +54,4 @@ class GeocodeTest extends KernelTestCase
         };
     }
 }
+