diff --git a/libraries/classmap.php b/libraries/classmap.php
index d6873aadb45be..e5afe6c216bc7 100644
--- a/libraries/classmap.php
+++ b/libraries/classmap.php
@@ -166,7 +166,6 @@
 JLoader::registerAlias('JToolbarButtonSeparator',           '\\Joomla\\CMS\\Toolbar\\Button\\SeparatorButton', '5.0');
 JLoader::registerAlias('JToolbarButtonSlider',              '\\Joomla\\CMS\\Toolbar\\Button\\SliderButton', '5.0');
 JLoader::registerAlias('JToolbarButtonStandard',            '\\Joomla\\CMS\\Toolbar\\Button\\StandardButton', '5.0');
-JLoader::registerAlias('JToolbarButtonStandard',            '\\Joomla\\CMS\\Toolbar\\Button\\StandardButton', '5.0');
 JLoader::registerAlias('JButton',                           '\\Joomla\\CMS\\Toolbar\\ToolbarButton', '5.0');
 
 JLoader::registerAlias('JVersion',                          '\\Joomla\\CMS\\Version', '5.0');