diff --git a/static/css/chat.css b/static/css/chat.css
index 1355f98..645707c 100644
--- a/static/css/chat.css
+++ b/static/css/chat.css
@@ -383,6 +383,10 @@ body:not(.loading) #loading {
 	background: #1b1d2a;
 }
 
+.tool .result pre.l-json .pre-header {
+	display: none;
+}
+
 .message .tool .result,
 .message .reasoning-text {
 	background: #1e2030;
diff --git a/static/js/markdown.js b/static/js/markdown.js
index 5c307ec..9f41cfa 100644
--- a/static/js/markdown.js
+++ b/static/js/markdown.js
@@ -41,7 +41,7 @@
 			code(code) {
 				const header = `<div class="pre-header">${escapeHtml(code.lang)}<button class="pre-copy" title="Copy code contents"></button></div>`;
 
-				return `<pre>${header}<code>${code.text}</code></pre>`;
+				return `<pre class="l-${escapeHtml(code.lang)}">${header}<code>${code.text}</code></pre>`;
 			},
 
 			link(link) {