diff --git a/src/Symfony/Component/HttpKernel/DataCollector/RequestDataCollector.php b/src/Symfony/Component/HttpKernel/DataCollector/RequestDataCollector.php
index fd66b38cd2..f274ac79c2 100644
--- a/src/Symfony/Component/HttpKernel/DataCollector/RequestDataCollector.php
+++ b/src/Symfony/Component/HttpKernel/DataCollector/RequestDataCollector.php
@@ -374,7 +374,7 @@ class RequestDataCollector extends DataCollector implements EventSubscriberInter
             );
         }
 
-        return (string) $controller ?: 'n/a';
+        return is_string($controller) ? $controller : 'n/a';
     }
 
     private function getCookieHeader($name, $value, $expires, $path, $domain, $secure, $httponly)
diff --git a/src/Symfony/Component/HttpKernel/Tests/DataCollector/RequestDataCollectorTest.php b/src/Symfony/Component/HttpKernel/Tests/DataCollector/RequestDataCollectorTest.php
index eef00d4a02..df5d974fd8 100644
--- a/src/Symfony/Component/HttpKernel/Tests/DataCollector/RequestDataCollectorTest.php
+++ b/src/Symfony/Component/HttpKernel/Tests/DataCollector/RequestDataCollectorTest.php
@@ -11,6 +11,7 @@
 
 namespace Symfony\Component\HttpKernel\Tests\DataCollector;
 
+use Symfony\Component\HttpFoundation\RedirectResponse;
 use Symfony\Component\HttpFoundation\Session\Session;
 use Symfony\Component\HttpFoundation\Session\Storage\MockArraySessionStorage;
 use Symfony\Component\HttpKernel\Controller\ArgumentResolverInterface;
@@ -70,16 +71,28 @@ class RequestDataCollectorTest extends \PHPUnit_Framework_TestCase
     }
 
     /**
-     * Test various types of controller callables.
+     * @dataProvider provideControllerCallables
      */
-    public function testControllerInspection()
+    public function testControllerInspection($name, $callable, $expected)
+    {
+        $c = new RequestDataCollector();
+        $request = $this->createRequest();
+        $response = $this->createResponse();
+        $this->injectController($c, $callable, $request);
+        $c->collect($request, $response);
+
+        $this->assertSame($expected, $c->getController(), sprintf('Testing: %s', $name));
+    }
+
+    public function provideControllerCallables()
     {
         // make sure we always match the line number
         $r1 = new \ReflectionMethod($this, 'testControllerInspection');
         $r2 = new \ReflectionMethod($this, 'staticControllerMethod');
         $r3 = new \ReflectionClass($this);
+
         // test name, callable, expected
-        $controllerTests = array(
+        return array(
             array(
                 '"Regular" callable',
                 array($this, 'testControllerInspection'),
@@ -168,15 +181,17 @@ class RequestDataCollectorTest extends \PHPUnit_Framework_TestCase
                 ),
             ),
         );
+    }
+
+    public function testItIgnoresInvalidCallables()
+    {
+        $request = $this->createRequestWithSession();
+        $response = new RedirectResponse('/');
 
         $c = new RequestDataCollector();
-        $request = $this->createRequest();
-        $response = $this->createResponse();
-        foreach ($controllerTests as $controllerTest) {
-            $this->injectController($c, $controllerTest[1], $request);
-            $c->collect($request, $response);
-            $this->assertSame($controllerTest[2], $c->getController(), sprintf('Testing: %s', $controllerTest[0]));
-        }
+        $c->collect($request, $response);
+
+        $this->assertSame('n/a', $c->getController());
     }
 
     protected function createRequest()
@@ -191,6 +206,16 @@ class RequestDataCollectorTest extends \PHPUnit_Framework_TestCase
         return $request;
     }
 
+    private function createRequestWithSession()
+    {
+        $request = $this->createRequest();
+        $request->attributes->set('_controller', 'Foo::bar');
+        $request->setSession(new Session(new MockArraySessionStorage()));
+        $request->getSession()->start();
+
+        return $request;
+    }
+
     protected function createResponse()
     {
         $response = new Response();