diff --git a/Provider.php b/Provider.php
index 122d0f9..cd7b45f 100644
--- a/Provider.php
+++ b/Provider.php
@@ -45,10 +45,7 @@ class Provider extends AbstractProvider
 
     protected $scopeSeparator = ' ';
 
-    /**
-     * {@inheritdoc}
-     */
-    protected function getAuthUrl($state)
+    protected function getAuthUrl($state): string
     {
         return
             $this->buildAuthUrlFromBase(
@@ -60,11 +57,7 @@ protected function getAuthUrl($state)
             );
     }
 
-    /**
-     * {@inheritdoc}
-     * https://developer.microsoft.com/en-us/graph/docs/concepts/use_the_api.
-     */
-    protected function getTokenUrl()
+    protected function getTokenUrl(): string
     {
         return sprintf('https://login.microsoftonline.com/%s/oauth2/v2.0/token', $this->getConfig('tenant', 'common'));
     }