diff --git a/event/main_listener.php b/event/main_listener.php
index 07ed675..4e19f2d 100644
--- a/event/main_listener.php
+++ b/event/main_listener.php
@@ -104,7 +104,6 @@ public function __construct(auth $auth, config $config, db_text $config_text, la
 	 */
 	public function add_custom_sites($event)
 	{
-		$is_phpbb4 = phpbb_version_compare($this->config['version'], '4.0.0-a1', '>=');
 		$phpbb4_builtins = array_flip([
 			'applepodcasts', 'bluesky', 'bunny', 'mastodon', 'pastebin', 'threads', 'twitter',
 		]);
@@ -114,7 +113,7 @@ public function add_custom_sites($event)
 			$name = basename($site, ext::YML);
 
 			// Skip built-in sites when running phpBB 4
-			if ($is_phpbb4 && isset($phpbb4_builtins[$name]))
+			if ($this->is_phpbb4() && isset($phpbb4_builtins[$name]))
 			{
 				continue;
 			}
@@ -178,7 +177,11 @@ public function modify_tag_templates($event)
 		{
 			// force YouTube to use the no cookies until the user starts video playback, and fix referrer policy issues
 			$tag = $event['configurator']->tags['YOUTUBE'];
-			$tag->template = str_replace(['www.youtube.com', ' allowfullscreen'], ['www.youtube-nocookie.com', ' referrerpolicy="origin" allowfullscreen'], $tag->template);
+			$tag->template = str_replace(['www.youtube.com'], 'www.youtube-nocookie.com', $tag->template);
+			if (!$this->is_phpbb4())
+			{
+				$tag->template = str_replace([' allowfullscreen'], ' referrerpolicy="origin" allowfullscreen', $tag->template);
+			}
 
 			$event['configurator']->finalize();
 		}
@@ -394,4 +397,12 @@ public function append_agreement()
 
 		$this->template->append_var('AGREEMENT_TEXT', $this->language->lang('MEDIA_EMBED_PRIVACY_POLICY', $this->config['sitename']));
 	}
+
+	/**
+	 * @return mixed
+	 */
+	private function is_phpbb4()
+	{
+		return phpbb_version_compare($this->config['version'], '4.0.0-a1', '>=');
+	}
 }