diff --git a/event/formatter_listener.php b/event/formatter_listener.php
index eb0c210..89a18bf 100644
--- a/event/formatter_listener.php
+++ b/event/formatter_listener.php
@@ -121,12 +121,7 @@ public function modify_tag_templates($event)
 	{
 		try
 		{
-			$tag = $event['configurator']->tags['YOUTUBE'];
-			$tag->template = str_replace('www.youtube.com', 'www.youtube-nocookie.com', $tag->template);
-			if (!$this->sites->is_phpbb4())
-			{
-				$tag->template = str_replace(' allowfullscreen', ' referrerpolicy="origin" allowfullscreen', $tag->template);
-			}
+			$this->configure_youtube($event['configurator']->tags['YOUTUBE']);
 		}
 		catch (\RuntimeException $e)
 		{
@@ -159,4 +154,31 @@ protected function get_site_ids()
 
 		return $site_ids ? json_decode($site_ids, true) : [];
 	}
+
+	/**
+	 * Apply YouTube privacy, compatibility, and Shorts rendering changes.
+	 *
+	 * @param s9e\TextFormatter\Configurator\Items\Tag $tag Tag to configure
+	 * @return void
+	 */
+	public function configure_youtube($tag)
+	{
+		$template = str_replace('www.youtube.com', 'www.youtube-nocookie.com', (string) $tag->template);
+		if (!$this->sites->is_phpbb4())
+		{
+			$template = str_replace(' allowfullscreen', ' referrerpolicy="origin" allowfullscreen', $template);
+		}
+
+		$shorts_template = str_replace(
+			['max-width:640px', 'padding-bottom:56.25%'],
+			['max-width:360px', 'padding-bottom:177.777778%'],
+			$template
+		);
+
+		$tag->template =
+			'<xsl:choose>' .
+				'<xsl:when test="contains(., \'/shorts/\')">' . $shorts_template . '</xsl:when>' .
+				'<xsl:otherwise>' . $template . '</xsl:otherwise>' .
+			'</xsl:choose>';
+	}
 }
diff --git a/tests/event/listener_test.php b/tests/event/listener_test.php
index 6cca606..871145e 100644
--- a/tests/event/listener_test.php
+++ b/tests/event/listener_test.php
@@ -185,6 +185,9 @@ public function test_youtube_template_uses_phpbb3_compatibility_fixes()
 		$template = $configurator->tags['YOUTUBE']->template;
 		$this->assertStringContainsString('www.youtube-nocookie.com', $template);
 		$this->assertStringContainsString('referrerpolicy="origin"', $template);
+		$this->assertStringContainsString('contains(., \'/shorts/\')', $template);
+		$this->assertStringContainsString('max-width:360px', $template);
+		$this->assertStringContainsString('padding-bottom:177.777778%', $template);
 	}
 
 	public function test_upstream_collection_is_skipped_on_phpbb4()
diff --git a/tests/functional/media_embed_test.php b/tests/functional/media_embed_test.php
index 4c95c92..47c5690 100644
--- a/tests/functional/media_embed_test.php
+++ b/tests/functional/media_embed_test.php
@@ -18,6 +18,7 @@
 class media_embed_test extends \phpbb_functional_test_case
 {
 	protected $youtubeId = 'PHzShhtkzEk';
+	protected $youtubeShortsId = 'xer3HqUWLkw';
 	protected $ok_ru_Id = '549000643961';
 
 	protected static function setup_extensions()
@@ -36,7 +37,7 @@ public function test_posting_media_bbcode()
 
 		$post = $this->create_topic($forum_id, 'Media Embed Test Topic 1', "[media]https://youtu.be/$this->youtubeId[/media]");
 		$crawler = self::request('GET', "viewtopic.php?t={$post['topic_id']}&sid=$this->sid");
-		self::assertStringContainsString("//www.youtube-nocookie.com/embed/$this->youtubeId", $crawler->filter("#post_content{$post['topic_id']} iframe")->attr('src'));
+		self::assertStringContainsString("//www.youtube-nocookie.com/embed/$this->youtubeId", $crawler->filter("#post_content{$post['post_id']} iframe")->attr('src'));
 	}
 
 	public function test_posting_custom_site()
@@ -50,7 +51,30 @@ public function test_posting_custom_site()
 
 		$post = $this->create_topic(2, 'Media Embed Custom Site Test Topic 1', "[media]https://ok.ru/video/$this->ok_ru_Id[/media]");
 		$crawler = self::request('GET', "viewtopic.php?t={$post['topic_id']}&sid=$this->sid");
-		self::assertStringContainsString("//ok.ru/videoembed/$this->ok_ru_Id", $crawler->filter("#post_content{$post['topic_id']} iframe")->attr('src'));
+		self::assertStringContainsString("//ok.ru/videoembed/$this->ok_ru_Id", $crawler->filter("#post_content{$post['post_id']} iframe")->attr('src'));
+	}
+
+	public function test_youtube_shorts_template()
+	{
+		$this->login();
+
+		$forum_id = 2;
+
+		$post = $this->create_topic(
+			$forum_id,
+			'YouTube Shorts vertical rendering test',
+			"https://youtube.com/shorts/$this->youtubeShortsId\nhttps://youtu.be/$this->youtubeId"
+		);
+		$crawler = self::request('GET', "viewtopic.php?t={$post['topic_id']}&sid=$this->sid");
+		$selector = '#post_content' . $post['post_id'] . ' span[data-s9e-mediaembed="youtube"]';
+		$embeds = $crawler->filter($selector);
+		$wrappers = $crawler->filter($selector . ' > span');
+		self::assertCount(2, $embeds);
+		self::assertCount(2, $wrappers);
+		self::assertStringContainsString('max-width:360px', $embeds->eq(0)->attr('style'));
+		self::assertStringContainsString('padding-bottom:177.777778%', $wrappers->eq(0)->attr('style'));
+		self::assertStringContainsString('max-width:640px', $embeds->eq(1)->attr('style'));
+		self::assertStringContainsString('padding-bottom:56.25%', $wrappers->eq(1)->attr('style'));
 	}
 
 	public function signatures_data()