diff --git a/package.json b/package.json
index af18af1..a438374 100644
--- a/package.json
+++ b/package.json
@@ -60,7 +60,8 @@
     "electron-store": "^10.1.0",
     "highlight.js": "^11.11.1",
     "html2pdf.js": "^0.10.1",
-    "marked": "^16.2.1",
+    "marked": "^17.0.3",
+    "marked-highlight": "^2.2.3",
     "pdf-lib": "^1.17.1",
     "pdfjs-dist": "^3.11.174",
     "pdfkit": "^0.14.0",
diff --git a/src/renderer.js b/src/renderer.js
index a128a64..0ef4568 100644
--- a/src/renderer.js
+++ b/src/renderer.js
@@ -5,11 +5,12 @@
 
 const { ipcRenderer } = require('electron');
 const marked = require('marked');
+const { markedHighlight } = require('marked-highlight');
 const DOMPurify = require('dompurify');
 const hljs = require('highlight.js');
 
-// Configure marked
-marked.setOptions({
+// Configure marked with highlight extension
+marked.use(markedHighlight({
     highlight: function(code, lang) {
         if (lang && hljs.getLanguage(lang)) {
             try {
@@ -19,7 +20,10 @@ marked.setOptions({
             }
         }
         return hljs.highlightAuto(code).value;
-    },
+    }
+}));
+
+marked.use({
     breaks: true,
     gfm: true
 });
diff --git a/tests/setup.js b/tests/setup.js
index 7c6bdaa..7090e7a 100644
--- a/tests/setup.js
+++ b/tests/setup.js
@@ -59,7 +59,7 @@ global.window.electronAPI = {
 // Mock marked library
 global.window.marked = {
   parse: jest.fn((text) => `<p>${text}</p>`),
-  setOptions: jest.fn()
+  use: jest.fn()
 };
 
 // Mock DOMPurify