diff --git a/README.md b/README.md
index 4f93c6d..1b36198 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,8 @@ composer require jbelien/oauth2-OpenStreetMap
 $OpenStreetMapProvider = new \JBelien\OAuth2\Client\Provider\OpenStreetMap([
     'clientId'     => 'yourId',          // The client ID assigned to you by OpenStreetMap.org
     'clientSecret' => 'yourSecret',      // The client password assigned to you by OpenStreetMap.org
-    'redirectUri'  => 'yourRedirectUri'  // The return URL you specified for your app on OpenStreetMap.org
+    'redirectUri'  => 'yourRedirectUri', // The return URL you specified for your app on OpenStreetMap.org
+    'dev'          => false              // Whether to use the OpenStreetMap test environment at https://master.apis.dev.openstreetmap.org/
 ]);
 
 // Get authorization code
diff --git a/src/Provider/OpenStreetMap.php b/src/Provider/OpenStreetMap.php
index 22986e4..5489119 100644
--- a/src/Provider/OpenStreetMap.php
+++ b/src/Provider/OpenStreetMap.php
@@ -12,7 +12,7 @@ class OpenStreetMap extends AbstractProvider
 {
     use BearerAuthorizationTrait;
 
-    private $dev = false;
+    protected $dev = false;
 
     public function __construct(array $options = [], array $collaborators = [])
     {