diff --git a/src/markup/syntax/highlighter/PhutilPygmentsSyntaxHighlighter.php b/src/markup/syntax/highlighter/PhutilPygmentsSyntaxHighlighter.php
--- a/src/markup/syntax/highlighter/PhutilPygmentsSyntaxHighlighter.php
+++ b/src/markup/syntax/highlighter/PhutilPygmentsSyntaxHighlighter.php
@@ -119,6 +119,7 @@
       'j' => 'objective-j',
       'jbst' => 'duel',
       'kid' => 'genshi',
+      'kt' => 'kotlin',
       'ksh' => 'bash',
       'less' => 'css',
       'lgt' => 'logtalk',