diff --git a/src/Entity/Session.php b/src/Entity/Session.php
index 767403c4..ab166253 100644
--- a/src/Entity/Session.php
+++ b/src/Entity/Session.php
@@ -209,7 +209,7 @@ class Session
             return $this->client;
         }
 
-        $this->client = $this->server->getStorage('client')->getBySession($this->getId());
+        $this->client = $this->server->getStorage('client')->getBySession($this);
         return $this->client;
     }
 
diff --git a/src/Storage/ClientInterface.php b/src/Storage/ClientInterface.php
index fa881356..267888f0 100644
--- a/src/Storage/ClientInterface.php
+++ b/src/Storage/ClientInterface.php
@@ -11,6 +11,8 @@
 
 namespace League\OAuth2\Server\Storage;
 
+use League\OAuth2\Server\Entity\Session;
+
 /**
  * Client storage interface
  */