diff --git a/plugins/installer/packageinstaller/tmpl/default.php b/plugins/installer/packageinstaller/tmpl/default.php
index 60f75e7aee403..5d68a7187b8da 100644
--- a/plugins/installer/packageinstaller/tmpl/default.php
+++ b/plugins/installer/packageinstaller/tmpl/default.php
@@ -10,9 +10,9 @@
 
 defined('_JEXEC') or die;
 
-use Joomla\CMS\Filesystem\FilesystemHelper;
 use Joomla\CMS\HTML\HTMLHelper;
 use Joomla\CMS\Language\Text;
+use Joomla\Filesystem\Helper as FilesystemHelper;
 
 /** @var \Joomla\Plugin\Installer\Package\Extension\PackageInstaller $this */
 
@@ -33,7 +33,7 @@
     );
 
 $return = $this->getApplication()->getInput()->getBase64('return');
-$maxSizeBytes = FilesystemHelper::fileUploadMaxSize(false);
+$maxSizeBytes = FilesystemHelper::getFileUploadMaxSize();
 $maxSize = HTMLHelper::_('number.bytes', $maxSizeBytes);
 ?>
 <legend><?php echo Text::_('PLG_INSTALLER_PACKAGEINSTALLER_UPLOAD_INSTALL_JOOMLA_EXTENSION'); ?></legend>