diff --git a/package.json b/package.json
index 676b08a83f..254c66f500 100644
--- a/package.json
+++ b/package.json
@@ -28,7 +28,6 @@
     "@rollup/plugin-commonjs": "^25.0.7",
     "@rollup/plugin-node-resolve": "^15.2.3",
     "@rollup/plugin-terser": "^0.4.4",
-    "@types/marked": "^4.3.2",
     "@types/pluralize": "0.0.33",
     "boxen": "^7.1.1",
     "chokidar": "^3.5.3",
@@ -89,7 +88,7 @@
   "dependencies": {
     "colors": "1.4.0",
     "finalhandler": "^1.2.0",
-    "marked": "^4.3.0",
+    "marked": "^11.1.1",
     "puppeteer": "^21.7.0",
     "sade": "^1.8.1",
     "serve-static": "^1.15.0"
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index bcf6fbe351..d54e9abeca 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -12,8 +12,8 @@ dependencies:
     specifier: ^1.2.0
     version: 1.2.0
   marked:
-    specifier: ^4.3.0
-    version: 4.3.0
+    specifier: ^11.1.1
+    version: 11.1.1
   puppeteer:
     specifier: ^21.7.0
     version: 21.7.0(typescript@5.3.3)
@@ -37,9 +37,6 @@ devDependencies:
   '@rollup/plugin-terser':
     specifier: ^0.4.4
     version: 0.4.4(rollup@4.9.4)
-  '@types/marked':
-    specifier: ^4.3.2
-    version: 4.3.2
   '@types/pluralize':
     specifier: 0.0.33
     version: 0.0.33
@@ -563,10 +560,6 @@ packages:
     resolution: {integrity: sha512-dRLjCWHYg4oaA77cxO64oO+7JwCwnIzkZPdrrC71jQmQtlhM556pwKo5bUzqvZndkVbeFLIIi+9TC40JNF5hNQ==}
     dev: true
 
-  /@types/marked@4.3.2:
-    resolution: {integrity: sha512-a79Yc3TOk6dGdituy8hmTTJXjOkZ7zsFYV10L337ttq/rec8lRMDBpV7fL3uLx6TgbFCa5DU/h8FmIBQPSbU0w==}
-    dev: true
-
   /@types/node@20.10.5:
     resolution: {integrity: sha512-nNPsNE65wjMxEKI93yOP+NPGGBJz/PoN3kZsVLee0XMiJolxSekEVD8wRwBUBqkwc7UWop0edW50yrCQW4CyRw==}
     dependencies:
@@ -2842,9 +2835,9 @@ packages:
       '@jridgewell/sourcemap-codec': 1.4.15
     dev: true
 
-  /marked@4.3.0:
-    resolution: {integrity: sha512-PRsaiG84bK+AMvxziE/lCFss8juXjNaWzVbN5tXAm4XjeaS9NAHhop+PjQxz2A9h8Q4M/xGmzP8vqNwy6JeK0A==}
-    engines: {node: '>= 12'}
+  /marked@11.1.1:
+    resolution: {integrity: sha512-EgxRjgK9axsQuUa/oKMx5DEY8oXpKJfk61rT5iY3aRlgU6QJtUcxU5OAymdhCvWvhYcd9FKmO5eQoX8m9VGJXg==}
+    engines: {node: '>= 18'}
     hasBin: true
     dev: false
 
diff --git a/src/core/markdown.js b/src/core/markdown.js
index c12bee1c45..89d750dbcf 100644
--- a/src/core/markdown.js
+++ b/src/core/markdown.js
@@ -7,16 +7,18 @@
  * property of the configuration object to "markdown."
  *
  * We use marked for parsing Markdown:
- * https://github.com/chjj/marked
+ * https://github.com/markedjs/marked
  *
  */
 
 import { getElementIndentation, reindent } from "./utils.js";
 import { marked } from "./import-maps.js";
+
 export const name = "core/markdown";
 
 const gtEntity = />/gm;
 const ampEntity = /&/gm;
+
 class Renderer extends marked.Renderer {
   code(code, infoString, isEscaped) {
     const { language, ...metaData } = Renderer.parseInfoString(infoString);
@@ -26,7 +28,9 @@ class Renderer extends marked.Renderer {
       return `<pre class="idl">${code}</pre>`;
     }
 
-    const html = super.code(code, language, isEscaped);
+    const html = super
+      .code(code, language, isEscaped)
+      .replace(`class="language-`, `class="`);
 
     const { example, illegalExample } = metaData;
     if (!example && !illegalExample) return html;
@@ -72,21 +76,19 @@ class Renderer extends marked.Renderer {
     return { language, ...metaData };
   }
 
-  heading(text, level, raw, slugger) {
+  heading(text, level, raw) {
     const headingWithIdRegex = /(.+)\s+{#([\w-]+)}$/;
     if (headingWithIdRegex.test(text)) {
       const [, textContent, id] = text.match(headingWithIdRegex);
       return `<h${level} id="${id}">${textContent}</h${level}>`;
     }
-    return super.heading(text, level, raw, slugger);
+    return super.heading(text, level, raw);
   }
 }
 
+/** @type {import('marked').MarkedOptions} */
 const config = {
-  sanitize: false,
   gfm: true,
-  headerIds: false,
-  langPrefix: "",
   renderer: new Renderer(),
 };
 
diff --git a/tests/spec/core/markdown-spec.js b/tests/spec/core/markdown-spec.js
index c720877dd7..4ddf553002 100644
--- a/tests/spec/core/markdown-spec.js
+++ b/tests/spec/core/markdown-spec.js
@@ -315,9 +315,7 @@ describe("Core - Markdown", () => {
     expect(webidlBlock.querySelector(".respec-button-copy-paste")).toBeTruthy();
 
     expect(jsBlock.firstElementChild.localName).toBe("code");
-    expect(
-      jsBlock.querySelector("code.hljs").classList.contains("js")
-    ).toBeTruthy();
+    expect(jsBlock.querySelector("code.hljs").classList).toContain("js");
     expect(jsBlock.querySelector("code.hljs span")).not.toBeNull();
     expect(jsBlock.querySelector(".respec-button-copy-paste")).toBeNull();