diff --git a/README.md b/README.md
index 0108faa..de52853 100644
--- a/README.md
+++ b/README.md
@@ -18,7 +18,7 @@ import hljs from 'highlight.js';
 const marked = new Marked(
   markedHighlight({
     langPrefix: 'hljs language-',
-    highlight(code, lang) {
+    highlight(code, lang, info) {
       const language = hljs.getLanguage(lang) ? lang : 'plaintext';
       return hljs.highlight(code, { language }).value;
     }
@@ -46,7 +46,7 @@ import pygmentize from 'pygmentize-bundled';
 const marked = new Marked(
   markedHighlight({
     async: true,
-    highlight(code, lang) {
+    highlight(code, lang, info) {
       return new Promise((resolve, reject) => {
         pygmentize({ lang, format: 'html' }, code, function (err, result) {
           if (err) {
diff --git a/spec/index.test.js b/spec/index.test.js
index a3deef3..27b21c6 100644
--- a/spec/index.test.js
+++ b/spec/index.test.js
@@ -174,4 +174,71 @@ no need to escape chars
 
     expect(() => marked(markdown)).toThrow(/set the async option to true/i);
   });
+
+  const markdownWithSpaceInLang = `
+\`\`\`ts twoslash
+let a = 1
+\`\`\``;
+
+  test('uses infostring', () => {
+    marked.use(markedHighlight({
+      highlight(code, lang, info) {
+        return info;
+      }
+    }));
+
+    expect(marked(markdownWithSpaceInLang)).toMatchInlineSnapshot(`
+"<pre><code class="language-ts">ts twoslash
+</code></pre>"
+`);
+  });
+
+  test('async uses infostring', async() => {
+    marked.use(markedHighlight({
+      async: true,
+      highlight(code, lang, info) {
+        return new Promise((resolve, reject) => {
+          resolve(info);
+        });
+      }
+    }));
+
+    expect(await marked(markdownWithSpaceInLang)).toMatchInlineSnapshot(`
+"<pre><code class="language-ts">ts twoslash
+</code></pre>"
+`);
+  });
+
+  const markdownWithoutLang = `
+\`\`\`
+no language provided
+\`\`\`
+`;
+
+  test('nullish infostring is cast to empty string', () => {
+    marked.use(markedHighlight({
+      highlight(code, lang, info) {
+        expect(info).toBe('');
+        return info;
+      }
+    }));
+    expect(marked(markdownWithoutLang)).toMatchInlineSnapshot(`
+"<pre><code>
+</code></pre>"
+`);
+  });
+
+  test('async nullish infostring is cast to empty string', async() => {
+    marked.use(markedHighlight({
+      async: true,
+      highlight(code, lang, info) {
+        expect(info).toBe('');
+        return Promise.resolve(info);
+      }
+    }));
+    expect(await marked(markdownWithoutLang)).toMatchInlineSnapshot(`
+"<pre><code>
+</code></pre>"
+`);
+  });
 });
diff --git a/src/index.d.ts b/src/index.d.ts
index 0162a9c..6a0a366 100644
--- a/src/index.d.ts
+++ b/src/index.d.ts
@@ -5,9 +5,11 @@ declare module 'marked-highlight' {
    * @param code The raw code to be highlighted
    * @param language The language tag found immediately after the code block
    *   opening marker (e.g. ```typescript -> language='typescript')
+   * @param info The full string after the code block opening marker
+   *   (e.g. ```ts twoslash -> info='ts twoslash')
    * @return The highlighted code as a HTML string
    */
-  type SyncHighlightFunction = (code: string, language: string) => string;
+  type SyncHighlightFunction = (code: string, language: string, info: string) => string;
 
   /**
    * An asynchronous function to highlight code
@@ -15,9 +17,11 @@ declare module 'marked-highlight' {
    * @param code The raw code to be highlighted
    * @param language The language tag found immediately after the code block
    *   opening marker (e.g. ```typescript -> language='typescript')
+   * @param info The full string after the code block opening marker
+   *   (e.g. ```ts twoslash -> info='ts twoslash')
    * @return A Promise for the highlighted code as a HTML string
    */
-  type AsyncHighlightFunction = (code: string, language: string) => Promise<string>;
+  type AsyncHighlightFunction = (code: string, language: string, info: string) => Promise<string>;
 
   /**
    * Options for configuring the marked-highlight extension using a synchronous
diff --git a/src/index.js b/src/index.js
index b267e4d..95afb42 100644
--- a/src/index.js
+++ b/src/index.js
@@ -23,10 +23,10 @@ export function markedHighlight(options) {
       const lang = getLang(token);
 
       if (options.async) {
-        return Promise.resolve(options.highlight(token.text, lang)).then(updateToken(token));
+        return Promise.resolve(options.highlight(token.text, lang, token.lang || '')).then(updateToken(token));
       }
 
-      const code = options.highlight(token.text, lang);
+      const code = options.highlight(token.text, lang, token.lang || '');
       if (code instanceof Promise) {
         throw new Error('markedHighlight is not set to async but the highlight function is async. Set the async option to true on markedHighlight to await the async highlight function.');
       }
diff --git a/types_test/index.test-d.ts b/types_test/index.test-d.ts
index acb6a0c..cfd9b7a 100644
--- a/types_test/index.test-d.ts
+++ b/types_test/index.test-d.ts
@@ -3,6 +3,7 @@ import {expectError} from 'tsd';
 
 // Single function argument
 markedHighlight((code: string, language: string) => code+language);
+markedHighlight((code: string, language: string, info: string) => code+language+info);
 
 // Invalid asynchronous function argument - missing async: true
 expectError(markedHighlight(async (code: string, language: string) => code+language));
@@ -37,6 +38,10 @@ markedHighlight({
   highlight: async (code: string, language: string) => code+language,
   async: true,
 })
+markedHighlight({
+  highlight: async (code: string, language: string, info: string) => code+language+info,
+  async: true,
+})
 
 // Full asynchronous options argument
 markedHighlight({