diff --git a/application/menunode.class.inc.php b/application/menunode.class.inc.php
index 612c2c5e5..791571d17 100644
--- a/application/menunode.class.inc.php
+++ b/application/menunode.class.inc.php
@@ -84,14 +84,10 @@ class ApplicationMenu
 		{
 			// Build menus from module handlers
 			//
-			foreach(get_declared_classes() as $sPHPClass)
-			{
-				if (is_subclass_of($sPHPClass, 'ModuleHandlerAPI'))
-				{
-					$aCallSpec = array($sPHPClass, 'OnMenuCreation');
-					call_user_func($aCallSpec);
-				}
-			}
+            foreach(MetaModel::EnumPlugins('ModuleHandlerApiInterface') as $oPHPClass)
+            {
+                $oPHPClass::OnMenuCreation();
+            }
 
 			// Build menus from the menus themselves (e.g. the ShortcutContainerMenuNode will do that)
 			//
diff --git a/core/metamodel.class.php b/core/metamodel.class.php
index aee4a756d..bfb629dc3 100644
--- a/core/metamodel.class.php
+++ b/core/metamodel.class.php
@@ -2599,7 +2599,7 @@ abstract class MetaModel
 
 		// Build the list of available extensions
 		//
-		$aInterfaces = array('iApplicationUIExtension', 'iApplicationObjectExtension', 'iQueryModifier', 'iOnClassInitialization', 'iPopupMenuExtension', 'iPageUIExtension', 'iPortalUIExtension');
+		$aInterfaces = array('iApplicationUIExtension', 'iApplicationObjectExtension', 'iQueryModifier', 'iOnClassInitialization', 'iPopupMenuExtension', 'iPageUIExtension', 'iPortalUIExtension', 'ModuleHandlerApiInterface');
 		foreach($aInterfaces as $sInterface)
 		{
 			self::$m_aExtensionClasses[$sInterface] = array();
@@ -5858,20 +5858,10 @@ abstract class MetaModel
 
 		CMDBSource::SelectDB(self::$m_sDBName);
 
-		foreach(get_declared_classes() as $sPHPClass)
-		{
-			if (is_subclass_of($sPHPClass, 'ModuleHandlerAPI'))
-			{
-				$aCallSpec = array($sPHPClass, 'OnMetaModelStarted');
-				call_user_func_array($aCallSpec, array());
-			}
-		}
-
-//		if (false)
-//		{
-//			echo "Debug<br/>\n";
-//			self::static_var_dump();
-//		}
+        foreach(MetaModel::EnumPlugins('ModuleHandlerApiInterface') as $oPHPClass)
+        {
+            $oPHPClass::OnMetaModelStarted();
+        }
 
 		ExpressionCache::Warmup();
 	}
diff --git a/core/modulehandler.class.inc.php b/core/modulehandler.class.inc.php
index 154bfc04b..d56307f63 100644
--- a/core/modulehandler.class.inc.php
+++ b/core/modulehandler.class.inc.php
@@ -25,7 +25,7 @@
  * @license     http://opensource.org/licenses/AGPL-3.0
  */
 
-abstract class ModuleHandlerAPI
+abstract class ModuleHandlerAPI implements ModuleHandlerApiInterface
 {
 	public static function OnMetaModelStarted()
 	{
@@ -34,5 +34,19 @@ abstract class ModuleHandlerAPI
 	public static function OnMenuCreation()
 	{
 	}
+
+	public function __construct()
+    {
+    }
+
 }
-?>
+
+
+interface ModuleHandlerApiInterface
+{
+    public static function OnMetaModelStarted();
+
+    public static function OnMenuCreation();
+
+    public function __construct(); //empty params is required in order to be instantiable by MetaModel::InitClasses()
+}
\ No newline at end of file