diff --git a/app/ErrorHandler.php b/app/ErrorHandler.php
index 5c7c776..0812d71 100644
--- a/app/ErrorHandler.php
+++ b/app/ErrorHandler.php
@@ -4,22 +4,22 @@
 
 use Crell\ApiProblem\ApiProblem;
 use CultuurNet\UDB3\HttpFoundation\Response\ApiProblemJsonResponse;
+use Exception;
 
 class ErrorHandler
 {
-
-    public function __invoke(\Exception $exception) : ApiProblem
+    public function __invoke(Exception $exception): ApiProblemJsonResponse
     {
         $problem = new ApiProblem($this->formatMessage($exception));
         $problem->setStatus($exception->getCode() ?: ApiProblemJsonResponse::HTTP_BAD_REQUEST);
-        return $problem;
+        return new ApiProblemJsonResponse($problem);
     }
 
     /**
-     * @param \Exception $exception
+     * @param Exception $exception
      * @return string
      */
-    private function formatMessage(\Exception $exception): string
+    private function formatMessage(Exception $exception): string
     {
         $message = $exception->getMessage();
         return preg_replace('/URL CALLED.*/', '', $message);
diff --git a/app/ErrorHandlerProvider.php b/app/ErrorHandlerProvider.php
index 6c2f99a..2c067e0 100644
--- a/app/ErrorHandlerProvider.php
+++ b/app/ErrorHandlerProvider.php
@@ -2,7 +2,6 @@
 
 namespace CultuurNet\UDB3\UiTPASService;
 
-use Exception;
 use Silex\Application;
 use Silex\ServiceProviderInterface;
 
@@ -10,11 +9,13 @@ class ErrorHandlerProvider implements ServiceProviderInterface
 {
     public function register(Application $app)
     {
-        $app->error(
-            function (Exception $e) {
-                return (new ErrorHandler())->__invoke($e);
+        $app['error_handler'] = $app::share(
+            function () {
+                return new ErrorHandler();
             }
         );
+
+        $app->error($app['error_handler']);
     }
 
     public function boot(Application $app)
diff --git a/tests/ErrorHandlerTest.php b/tests/ErrorHandlerTest.php
index 492b1ca..730950e 100644
--- a/tests/ErrorHandlerTest.php
+++ b/tests/ErrorHandlerTest.php
@@ -2,6 +2,7 @@
 
 namespace CultuurNet\UDB3\UiTPASService;
 
+use Exception;
 use PHPUnit\Framework\TestCase;
 
 class ErrorHandlerTest extends TestCase
@@ -11,12 +12,16 @@ class ErrorHandlerTest extends TestCase
      */
     public function it_creates_api_problem_from_exception()
     {
-        $exception = new \Exception('Exception message', 500);
+        $exception = new Exception('Exception message', 500);
 
         $errorHandler = new ErrorHandler();
-        $apiProblem = $errorHandler->__invoke($exception);
-        $this->assertEquals('Exception message', $apiProblem->getTitle());
-        $this->assertEquals(500, $apiProblem->getStatus());
+        $apiProblemResponse = $errorHandler->__invoke($exception);
+
+        $this->assertEquals(
+            '{"title":"Exception message","type":"about:blank","status":500}',
+            $apiProblemResponse->getContent()
+        );
+        $this->assertEquals(500, $apiProblemResponse->getStatusCode());
     }
 
     /**
@@ -24,12 +29,16 @@ public function it_creates_api_problem_from_exception()
      */
     public function it_creates_api_problem_with_400_status_if_exception_has_no_status_code()
     {
-        $exception = new \Exception('Exception message');
+        $exception = new Exception('Exception message');
 
         $errorHandler = new ErrorHandler();
-        $apiProblem = $errorHandler->__invoke($exception);
-        $this->assertEquals('Exception message', $apiProblem->getTitle());
-        $this->assertEquals(400, $apiProblem->getStatus());
+        $apiProblemResponse = $errorHandler->__invoke($exception);
+
+        $this->assertEquals(
+            '{"title":"Exception message","type":"about:blank","status":400}',
+            $apiProblemResponse->getContent()
+        );
+        $this->assertEquals(400, $apiProblemResponse->getStatusCode());
     }
 
     /**
@@ -39,10 +48,14 @@ public function it_strips_URL_CALLED_from_api_problem_message_title()
     {
         // the resulting ApiProblem title should be stripped
         // of everything after URL CALLED
-        $exception = new \Exception('Exception message URL CALLED: https://acc.uitid.be/uitid/rest/uitpas/cultureevent/de343e38-d656-4928-96bc-55578e0d94ec/cardsystems POST DATA: cardSystemId=3');
+        $exception = new Exception('Exception message URL CALLED: https://acc.uitid.be/uitid/rest/uitpas/cultureevent/de343e38-d656-4928-96bc-55578e0d94ec/cardsystems POST DATA: cardSystemId=3');
 
         $errorHandler = new ErrorHandler();
-        $apiProblem = $errorHandler->__invoke($exception);
-        $this->assertEquals('Exception message ', $apiProblem->getTitle());
+        $apiProblemResponse = $errorHandler->__invoke($exception);
+
+        $this->assertEquals(
+            '{"title":"Exception message ","type":"about:blank","status":400}',
+            $apiProblemResponse->getContent()
+        );
     }
 }