diff --git a/plugins/Prism.php b/plugins/Prism.php
index b5b9803..9af5473 100644
--- a/plugins/Prism.php
+++ b/plugins/Prism.php
@@ -15,12 +15,16 @@ class Prism
 		<script<?= nonce() ?>>
 			document.addEventListener('DOMContentLoaded', function () {
 				document.querySelectorAll('[class^=jush-]').forEach(function ($item) {
-					let jush = $item.getAttribute('class').trim();
-					let lang = jush.replace('jush-', 'language-');
-					$item.setAttribute('class', lang);
-					// $item.classList.remove(jush);
-					// $item.classList.add(lang);
+					const current_class = $item.getAttribute('class').trim();
+					const language_class = current_class.replace('jush-', 'language-');
+					$item.setAttribute('class', language_class);
 				});
+				document.querySelectorAll('code').forEach(function ($item) {
+					const current_class = ($item.getAttribute('class') || '').trim();
+					if (current_class === '') {
+						$item.setAttribute('class', 'language-plain');
+					}
+				})
 			});
 		</script>
 		<link rel="stylesheet" type="text/css" href="assets/prism.css?<?= filemtime(__DIR__ . '/../assets/prism.js') ?>"/>