diff --git a/core/lib/Drupal/Core/Routing/RequestContext.php b/core/lib/Drupal/Core/Routing/RequestContext.php
index fd0afc9..4f64a79 100644
--- a/core/lib/Drupal/Core/Routing/RequestContext.php
+++ b/core/lib/Drupal/Core/Routing/RequestContext.php
@@ -11,15 +11,34 @@
 use Symfony\Component\Routing\RequestContext as BaseRequestContext;
 
 /**
- * Extends Symfony's RequestContext to populate pathInfo from _system_path.
+ * Extends Symfony's RequestContext to also provide system_path.
  */
 class RequestContext extends BaseRequestContext {
 
+  /**
+   * The requested internal path, with path aliases converted.
+   *
+   * @var string
+   */
+  protected $systemPath;
+
   public function fromRequest(Request $request) {
     parent::fromRequest($request);
     if ($request->attributes->has('_system_path')) {
-      $this->setPathInfo('/' . $request->attributes->get('_system_path'));
+      $this->systemPath = '/' . $request->attributes->get('_system_path');
+    }
+    else {
+      $this->systemPath = $this->getPathInfo();
     }
   }
 
+  /**
+   * The requested internal path.
+   *
+   * @return string
+   */
+  public function getSystemPath() {
+    return $this->systemPath;
+  }
+
 }
diff --git a/core/lib/Drupal/Core/Routing/RouteProvider.php b/core/lib/Drupal/Core/Routing/RouteProvider.php
index 56a3850..398f242 100644
--- a/core/lib/Drupal/Core/Routing/RouteProvider.php
+++ b/core/lib/Drupal/Core/Routing/RouteProvider.php
@@ -105,7 +105,7 @@ public function getRouteCollectionForRequest(Request $request) {
 
     $context = new RequestContext();
     $context->fromRequest($request);
-    $path = rtrim($context->getPathInfo(), '/');
+    $path = rtrim($context->getSystemPath(), '/');
 
     $collection = $this->getRoutesByPath($path);
 
diff --git a/core/lib/Drupal/Core/Routing/UrlMatcher.php b/core/lib/Drupal/Core/Routing/UrlMatcher.php
index 6f22cf6..def7b25 100644
--- a/core/lib/Drupal/Core/Routing/UrlMatcher.php
+++ b/core/lib/Drupal/Core/Routing/UrlMatcher.php
@@ -29,7 +29,7 @@ public function finalMatch(RouteCollection $collection, Request $request) {
     $context = new RequestContext();
     $context->fromRequest($request);
     $this->setContext($context);
-    $path = rtrim($context->getPathInfo(), '/');
+    $path = rtrim($context->getSystemPath(), '/');
     return $this->match($path);
   }
 
diff --git a/core/modules/user/lib/Drupal/user/EventSubscriber/MaintenanceModeSubscriber.php b/core/modules/user/lib/Drupal/user/EventSubscriber/MaintenanceModeSubscriber.php
index a881154..ca5b425 100644
--- a/core/modules/user/lib/Drupal/user/EventSubscriber/MaintenanceModeSubscriber.php
+++ b/core/modules/user/lib/Drupal/user/EventSubscriber/MaintenanceModeSubscriber.php
@@ -30,7 +30,7 @@ public function onKernelRequestMaintenance(GetResponseEvent $event) {
     $site_status = $request->attributes->get('_maintenance');
     $request_context = new RequestContext();
     $request_context->fromRequest($request);
-    $path = trim($request_context->getPathInfo(), '/');
+    $path = trim($request_context->getSystemPath(), '/');
     if ($site_status == MENU_SITE_OFFLINE) {
       // If the site is offline, log out unprivileged users.
       if ($user->isAuthenticated() && !$user->hasPermission('access site in maintenance mode')) {