diff --git a/src/Plugin/Field/FieldWidget/RedirectSourceWidget.php b/src/Plugin/Field/FieldWidget/RedirectSourceWidget.php
index 0aae50c..0aeffeb 100644
--- a/src/Plugin/Field/FieldWidget/RedirectSourceWidget.php
+++ b/src/Plugin/Field/FieldWidget/RedirectSourceWidget.php
@@ -8,6 +8,7 @@ use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\Core\Field\WidgetBase;
 use Drupal\Core\Url;
 use Drupal\Core\Form\FormStateInterface;
+use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
 use Symfony\Component\Routing\Exception\ResourceNotFoundException;
 
 /**
@@ -71,6 +72,9 @@ class RedirectSourceWidget extends WidgetBase {
         catch (ResourceNotFoundException $e) {
           // Do nothing, expected behaviour.
         }
+        catch (AccessDeniedHttpException $e) {
+          // @todo Source lookup results in an access denied, deny access?
+        }
 
         // Warning about the path being already redirected.
         $parsed_url = UrlHelper::parse($source_path);
diff --git a/tests/src/FunctionalJavascript/RedirectJavascriptTest.php b/tests/src/FunctionalJavascript/RedirectJavascriptTest.php
index c31fa9c..9feed93 100644
--- a/tests/src/FunctionalJavascript/RedirectJavascriptTest.php
+++ b/tests/src/FunctionalJavascript/RedirectJavascriptTest.php
@@ -194,7 +194,7 @@ class RedirectJavascriptTest extends WebDriverTestBase {
     $page->fillField('redirect_source[0][path]', '/page-to-redirect');
     $page->fillField('redirect_redirect[0][uri]', '/node');
     // Wait on ajax is unpredictable, wait for one second.
-    sleep(1);
+    $this->assertSession()->assertWaitOnAjaxRequest();
     $page->pressButton('Save');
     $this->assertRaw(t('The url to redirect from should not start with a forward slash (/).'));