diff --git a/libraries/joomla/event/dispatcher.php b/libraries/joomla/event/dispatcher.php
index f64108a192..39e3220054 100644
--- a/libraries/joomla/event/dispatcher.php
+++ b/libraries/joomla/event/dispatcher.php
@@ -97,8 +97,8 @@ public function getState()
 	 */
 	public function register($event, $handler)
 	{
-		// Are we dealing with a class or function type handler?
-		if (function_exists($handler))
+		// Are we dealing with a class or callback type handler?
+		if (is_callable($handler))
 		{
 			// Ok, function type event handler... let's attach it.
 			$method = array('event' => $event, 'handler' => $handler);