diff --git a/plugins/system/sef/src/Extension/Sef.php b/plugins/system/sef/src/Extension/Sef.php
index d431f6b18e2e..927eeffa8133 100644
--- a/plugins/system/sef/src/Extension/Sef.php
+++ b/plugins/system/sef/src/Extension/Sef.php
@@ -29,14 +29,6 @@
  */
 final class Sef extends CMSPlugin implements SubscriberInterface
 {
-    /**
-     * Application object.
-     *
-     * @var    \Joomla\CMS\Application\CMSApplication
-     * @since  __DEPLOY_VERSION__
-     */
-    protected $app;
-
     /**
      * Returns an array of CMS events this plugin will listen to and the respective handlers.
      *
@@ -69,7 +61,7 @@ public function onAfterInitialiseRouter(AfterInitialiseRouterEvent $event)
     {
         if (
             is_a($event->getRouter(), SiteRouter::class)
-            && $this->app->get('sef_rewrite')
+            && $this->getApplication()->get('sef_rewrite')
             && $this->params->get('indexphp')
         ) {
             // Enforce removing index.php with a redirect
@@ -78,8 +70,8 @@ public function onAfterInitialiseRouter(AfterInitialiseRouterEvent $event)
 
         if (
             is_a($event->getRouter(), SiteRouter::class)
-            && $this->app->get('sef')
-            && !$this->app->get('sef_suffix')
+            && $this->getApplication()->get('sef')
+            && !$this->getApplication()->get('sef_suffix')
             && $this->params->get('trailingslash')
         ) {
             if ($this->params->get('trailingslash') == 1) {
@@ -270,7 +262,7 @@ function ($match) use ($base, $protocols) {
     public function removeIndexphp(&$router, &$uri)
     {
         // We only want to redirect on GET requests
-        if ($this->app->getInput()->getMethod() !== 'GET') {
+        if ($this->getApplication()->getInput()->getMethod() !== 'GET') {
             return;
         }
 
@@ -279,13 +271,13 @@ public function removeIndexphp(&$router, &$uri)
         if (substr($origUri->getPath(), -9) === 'index.php') {
             // Remove trailing index.php
             $origUri->setPath(substr($origUri->getPath(), 0, -9));
-            $this->app->redirect($origUri->toString(), 301);
+            $this->getApplication()->redirect($origUri->toString(), 301);
         }
 
         if (substr($origUri->getPath(), \strlen(Uri::base(true)), 11) === '/index.php/') {
             // Remove leading index.php
             $origUri->setPath(Uri::base(true) . substr($origUri->getPath(), \strlen(Uri::base(true)) + 10));
-            $this->app->redirect($origUri->toString(), 301);
+            $this->getApplication()->redirect($origUri->toString(), 301);
         }
     }
 
@@ -340,7 +332,7 @@ public function addTrailingSlash(&$router, &$uri)
     public function enforceTrailingSlash(&$router, &$uri)
     {
         // We only want to redirect on GET requests
-        if ($this->app->getInput()->getMethod() != 'GET') {
+        if ($this->getApplication()->getInput()->getMethod() != 'GET') {
             return;
         }
 
@@ -349,11 +341,11 @@ public function enforceTrailingSlash(&$router, &$uri)
         if ($this->params->get('trailingslash') == 1 && substr($originalUri->getPath(), -1) == '/' && $originalUri->toString() != Uri::root()) {
             // Remove trailingslash
             $originalUri->setPath(substr($originalUri->getPath(), 0, -1));
-            $this->app->redirect($originalUri->toString(), 301);
+            $this->getApplication()->redirect($originalUri->toString(), 301);
         } elseif ($this->params->get('trailingslash') == 2 && substr($originalUri->getPath(), -1) != '/') {
             // Add trailingslash
             $originalUri->setPath($originalUri->getPath() . '/');
-            $this->app->redirect($originalUri->toString(), 301);
+            $this->getApplication()->redirect($originalUri->toString(), 301);
         }
     }