diff --git a/src/index.ts b/src/index.ts
index d691ec5..0d79484 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -345,6 +345,8 @@ export default function rehypePrettyCode(
           defaultCodeBlockLang,
         );
 
+        if (!lang) return;
+
         const lineNumbers: number[] = [];
         if (meta) {
           const matches = meta.matchAll(/\{(.*?)\}/g);
diff --git a/test/fixtures.test.js b/test/fixtures.test.js
index 713fa27..96d5f60 100644
--- a/test/fixtures.test.js
+++ b/test/fixtures.test.js
@@ -44,6 +44,10 @@ const runFixture = async (fixture, fixtureName, getHighlighter) => {
   const html = await getHTML(code, {
     keepBackground: !resultHTMLName.includes('keepBackground'),
     defaultLang: (() => {
+      if (testName === 'no-highlighting') {
+        return undefined;
+      }
+
       const lang = testName.split('.')[1];
       if (!lang) {
         return undefined;
diff --git a/test/fixtures/no-highlighting.md b/test/fixtures/no-highlighting.md
new file mode 100644
index 0000000..59f076b
--- /dev/null
+++ b/test/fixtures/no-highlighting.md
@@ -0,0 +1,3 @@
+```
+test
+```
diff --git a/test/results/defaultLang.inline=js.html b/test/results/defaultLang.inline=js.html
index a77fd54..8748e17 100644
--- a/test/results/defaultLang.inline=js.html
+++ b/test/results/defaultLang.inline=js.html
@@ -53,14 +53,8 @@
 </style>
 <h2>Default language</h2>
 <p>{ inline: 'js' }</p>
-<figure data-rehype-pretty-code-figure="">
-  <pre
-    style="background-color: #24292e; color: #e1e4e8"
-    tabindex="0"
-    data-language=""
-    data-theme="github-dark"
-  ><code data-language="" data-theme="github-dark" style="display: grid;"><span data-line=""><span>const x = true;</span></span></code></pre>
-</figure>
+<pre><code>const x = true;
+</code></pre>
 <p>
   <span data-rehype-pretty-code-figure=""
     ><code
diff --git a/test/results/no-highlighting.html b/test/results/no-highlighting.html
new file mode 100644
index 0000000..03cbb6c
--- /dev/null
+++ b/test/results/no-highlighting.html
@@ -0,0 +1,55 @@
+
+<style>
+  html {
+    font-family: -apple-system,BlinkMacSystemFont,"Segoe UI",Helvetica,Arial,sans-serif;
+  }
+  body {
+    margin: 30px auto;
+    max-width: 800px;
+  }
+  pre {
+    padding: 16px;
+  }
+  span > code {
+    background: black;
+    padding: 4px;
+  }
+  [data-highlighted-line], [data-highlighted-chars] {
+    background-color: rgba(255, 255, 255, 0.25);
+  }
+  code[data-line-numbers] {
+    counter-reset: line;
+  }
+  code[data-line-numbers]>[data-line]::before {
+    counter-increment: line;
+    content: counter(line);
+    display: inline-block;
+    width: 1rem;
+    margin-right: 2rem;
+    text-align: right;
+    color: gray;
+  }
+
+  [data-rehype-pretty-code-figure] code[data-theme*=' '],
+  [data-rehype-pretty-code-figure] code[data-theme*=' '] span {
+    color: var(--shiki-light) !important;
+    background-color: var(--shiki-light-bg) !important;
+  }
+
+  @media (prefers-color-scheme: dark) {
+    [data-rehype-pretty-code-figure] code[data-theme*=' '],
+    [data-rehype-pretty-code-figure] code[data-theme*=' '] span {
+      color: var(--shiki-dark) !important;
+      background-color: var(--shiki-dark-bg) !important;
+    }
+  }
+
+  .diff.add {
+    background-color: rgba(0, 255, 100, 0.25);
+  }
+  .diff.remove {
+    background-color: rgba(255, 100, 200, 0.35);
+  }
+</style>
+<pre><code>test
+</code></pre>