diff --git a/phpgwapi/inc/xajax/xajax_core/xajax.inc.php b/phpgwapi/inc/xajax/xajax_core/xajax.inc.php
index 8215ac08f4..133571fd27 100644
--- a/phpgwapi/inc/xajax/xajax_core/xajax.inc.php
+++ b/phpgwapi/inc/xajax/xajax_core/xajax.inc.php
@@ -254,12 +254,12 @@ class xajax
 		$sLocalFolder = dirname(__FILE__);
 
 //SkipAIO
-		require $sLocalFolder . '/xajaxPluginManager.inc.php';
-		require $sLocalFolder . '/xajaxLanguageManager.inc.php';
-		require $sLocalFolder . '/xajaxArgumentManager.inc.php';
-		require $sLocalFolder . '/xajaxResponseManager.inc.php';
-		require $sLocalFolder . '/xajaxRequest.inc.php';
-		require $sLocalFolder . '/xajaxResponse.inc.php';
+		require_once $sLocalFolder . '/xajaxPluginManager.inc.php';
+		require_once $sLocalFolder . '/xajaxLanguageManager.inc.php';
+		require_once $sLocalFolder . '/xajaxArgumentManager.inc.php';
+		require_once $sLocalFolder . '/xajaxResponseManager.inc.php';
+		require_once $sLocalFolder . '/xajaxRequest.inc.php';
+		require_once $sLocalFolder . '/xajaxResponse.inc.php';
 //EndSkipAIO
 
 		// this is the list of folders where xajax will look for plugins
diff --git a/phpgwapi/inc/xajax/xajax_core/xajaxPluginManager.inc.php b/phpgwapi/inc/xajax/xajax_core/xajaxPluginManager.inc.php
index f44db4c9db..b7fde478b4 100644
--- a/phpgwapi/inc/xajax/xajax_core/xajaxPluginManager.inc.php
+++ b/phpgwapi/inc/xajax/xajax_core/xajaxPluginManager.inc.php
@@ -19,7 +19,7 @@
 */
 
 //SkipAIO
-require(dirname(__FILE__) . '/xajaxPlugin.inc.php');
+require_once(dirname(__FILE__) . '/xajaxPlugin.inc.php');
 //EndSkipAIO
 
 /*
@@ -112,7 +112,7 @@ class xajaxPluginManager
 						$sFileName = substr($sName, 0, $nLength - 8);
 						$sExtension = substr($sName, $nLength - 8, 8);
 						if ('.inc.php' == $sExtension) {
-							require $sFolder . '/' . $sFileName . $sExtension;
+							require_once $sFolder . '/' . $sFileName . $sExtension;
 						}
 					}
 				}