Index: typo3/sysext/install/mod/class.tx_install.php
===================================================================
--- typo3/sysext/install/mod/class.tx_install.php	(revision 10331)
+++ typo3/sysext/install/mod/class.tx_install.php	(revision )
@@ -282,6 +282,13 @@
 			header('Pragma: no-cache');
 		}
 
+		if (!t3lib_extMgm::isLoaded('em')) {
+			$classes = require_once(dirname(__FILE__) . '../../em/ext_autoload.php');
+			foreach($classes as $file) {
+				require_once($file);
+			}
+		}
+
 			// ****************************
 			// Initializing incoming vars.
 			// ****************************