diff --git a/phpBB/includes/event/kernel_compiler_pass.php b/phpBB/includes/event/kernel_compiler_pass.php
index 18b6661cd4..9a650bc404 100644
--- a/phpBB/includes/event/kernel_compiler_pass.php
+++ b/phpBB/includes/event/kernel_compiler_pass.php
@@ -44,10 +44,7 @@ class phpbb_event_kernel_compiler_pass implements CompilerPassInterface
 
 				if (!isset($event['method']))
 				{
-					$event['method'] = 'on'.preg_replace(array(
-						'/(?<=\b)[a-z]/ie',
-						'/[^a-z0-9]/i'
-					), array('strtoupper("\\0")', ''), $event['event']);
+					throw new InvalidArgumentException($user->lang('NO_METHOD_ATTRIBUTE', $id));
 				}
 
 				$definition->addMethodCall('addListenerService', array($event['event'], array($id, $event['method']), $priority));
diff --git a/phpBB/language/en/app.php b/phpBB/language/en/app.php
index db7f3164d0..2cbeaa2cba 100644
--- a/phpBB/language/en/app.php
+++ b/phpBB/language/en/app.php
@@ -49,6 +49,7 @@ $lang = array_merge($lang, array(
 
 	// Event Listener/Subscriber error messages
 	'NO_EVENT_ATTRIBUTE'				=> 'Service "%1$s" must define the "event" attribute on "kernel.event_listener" tags.',
+	'NO_METHOD_ATTRIBUTE'				=> 'Service "%1$s" must define the "method" attribute on "kernel.event_listener" tags.',
 	'SUBSCRIBER_WRONG_TYPE'				=> 'Service "%1$s" must implement interface "%2$s".',
 
 	// Core error controller messages