diff --git a/README.md b/README.md
index 0b068a5..465eb51 100644
--- a/README.md
+++ b/README.md
@@ -128,7 +128,6 @@ And create the service definition, e.g.:
 <service id="app.admin.authenticator" class="AppBundle\Security\AdminAuthenticator">
     <argument type="service" id="router"/>
     <argument type="service" id="ssp.guard.registry"/>
-    <argument>admin</argument> <!-- this is the authsource id -->
 </service>
 ```
 
@@ -136,7 +135,7 @@ or in `app/config/services.yml`:
 
 ```yml
 AppBundle\Security\AdminAuthenticator:
-    arguments: ["@router", "@ssp.guard.registry", "admin"] 
+    arguments: ["@router", "@ssp.guard.registry"]
 ```
 
 ### Step 6: Create a custom User Provider
diff --git a/Security/Authenticator/SSPGuardAuthenticator.php b/Security/Authenticator/SSPGuardAuthenticator.php
index a7dcb12..ed92767 100644
--- a/Security/Authenticator/SSPGuardAuthenticator.php
+++ b/Security/Authenticator/SSPGuardAuthenticator.php
@@ -35,10 +35,6 @@ abstract class SSPGuardAuthenticator extends AbstractGuardAuthenticator
      * @var SSPAuthSource
      */
     protected $authSource = null;
-    /**
-     * @var
-     */
-    protected $authSourceId;
 
     /**
      * SSPGuardAuthenticator constructor.
@@ -46,11 +42,10 @@ abstract class SSPGuardAuthenticator extends AbstractGuardAuthenticator
      * @param Router $router
      * @param AuthSourceRegistry $authSourceRegistry
      */
-    public function __construct(Router $router, AuthSourceRegistry $authSourceRegistry, $authSourceId)
+    public function __construct(Router $router, AuthSourceRegistry $authSourceRegistry)
     {
         $this->router = $router;
         $this->authSourceRegistry = $authSourceRegistry;
-        $this->authSourceId = $authSourceId;
     }
 
     /**
@@ -59,8 +54,7 @@ public function __construct(Router $router, AuthSourceRegistry $authSourceRegist
     public function supports(Request $request)
     {
         $match = $this->router->match($request->getPathInfo());
-        return 'ssp_guard_check' === $match['_route'] &&
-            $this->authSourceId === $match['authSource'];
+        return 'ssp_guard_check' === $match['_route'];
     }
 
     /**
@@ -68,7 +62,8 @@ public function supports(Request $request)
      */
     public function getCredentials(Request $request)
     {
-        $this->authSource = $this->authSourceRegistry->getAuthSource($this->authSourceId);
+        $match = $this->router->match($request->getPathInfo());
+        $this->authSource = $this->authSourceRegistry->getAuthSource($match['authSource']);
 
         return $this->authSource->getCredentials();
     }
@@ -112,4 +107,4 @@ public function supportsRememberMe()
     {
         return true;
     }
-}
\ No newline at end of file
+}