diff --git a/docs/USING_ADVANCED.md b/docs/USING_ADVANCED.md
index df76a5018c..500eacc533 100644
--- a/docs/USING_ADVANCED.md
+++ b/docs/USING_ADVANCED.md
@@ -47,7 +47,7 @@ console.log(myMarked('I am using __markdown__.'));
 |headerIds   |`boolean` |`true`   |v0.4.0   |If true, include an `id` attribute when emitting headings (h1, h2, h3, etc).|
 |headerPrefix|`string`  |`''`     |???      |A string to prefix the `id` attribute when emitting headings (h1, h2, h3, etc).|
 |highlight   |`function`|`null`   |???      |A function to highlight code blocks, see <a href="#highlight">Asynchronous highlighting</a>.|
-|langPrefix  |`string`  |`'lang-'`|???      |A string to prefix the className in a `<code>` block. Useful for syntax highlighting.|
+|langPrefix  |`string`  |`'language-'`|???      |A string to prefix the className in a `<code>` block. Useful for syntax highlighting.|
 |mangle      |`boolean` |`true`   |???      |???     |
 |pedantic    |`boolean` |`false`  |???      |If true, conform to the original `markdown.pl` as much as possible. Don't fix original markdown bugs or behavior. Turns off and overrides `gfm`.|
 |renderer    |`object`  |`new Renderer()`|???|An object containing functions to render tokens to HTML. See [extensibility](USING_PRO.md) for more details.|
diff --git a/lib/marked.js b/lib/marked.js
index b929ffb5d4..33c02d9cf4 100644
--- a/lib/marked.js
+++ b/lib/marked.js
@@ -1470,7 +1470,7 @@ marked.getDefaults = function () {
     headerIds: true,
     headerPrefix: '',
     highlight: null,
-    langPrefix: 'lang-',
+    langPrefix: 'language-',
     mangle: true,
     pedantic: false,
     renderer: new Renderer(),
diff --git a/test/new/gfm_code.html b/test/new/gfm_code.html
index 438acdf8eb..0e8c693196 100644
--- a/test/new/gfm_code.html
+++ b/test/new/gfm_code.html
@@ -1,16 +1,16 @@
-<pre><code class="lang-js">var a = &#39;hello&#39;;
+<pre><code class="language-js">var a = &#39;hello&#39;;
 console.log(a + &#39; world&#39;);</code></pre>
-<pre><code class="lang-bash">echo &quot;hello, ${WORLD}&quot;</code></pre>
-<pre><code class="lang-longfence">Q: What do you call a tall person who sells stolen goods?</code></pre>
-<pre><code class="lang-ManyTildes">A longfence!</code></pre>
+<pre><code class="language-bash">echo &quot;hello, ${WORLD}&quot;</code></pre>
+<pre><code class="language-longfence">Q: What do you call a tall person who sells stolen goods?</code></pre>
+<pre><code class="language-ManyTildes">A longfence!</code></pre>
 <p>How about an empty code block?</p>
-<pre><code class="lang-js"></code></pre>
+<pre><code class="language-js"></code></pre>
 <p>How about a code block with only an empty line?</p>
-<pre><code class="lang-js">
+<pre><code class="language-js">
 </code></pre>
 
 <p>With some trailing empty lines:</p>
 <pre><code>ciao
 
 
-</code></pre>
\ No newline at end of file
+</code></pre>
diff --git a/test/new/gfm_code_hr_list.html b/test/new/gfm_code_hr_list.html
index 9fbd0fb9dd..d15b52fe02 100644
--- a/test/new/gfm_code_hr_list.html
+++ b/test/new/gfm_code_hr_list.html
@@ -22,11 +22,11 @@ <h2 id="foo">foo</h2>
 <li><p>foo:</p>
 <ol>
 <li><p>foo <code>bar</code> bar:</p>
-<pre><code class="lang-erb"> some code here
+<pre><code class="language-erb"> some code here
 </code></pre>
 </li>
 <li><p>foo <code>bar</code> bar:</p>
-<pre><code class="lang-erb"> foo
+<pre><code class="language-erb"> foo
  ---
  bar
  ---
@@ -34,7 +34,7 @@ <h2 id="foo">foo</h2>
  bar</code></pre>
 </li>
 <li><p>foo <code>bar</code> bar:</p>
-<pre><code class="lang-html"> ---
+<pre><code class="language-html"> ---
  foo
  foo
  ---
diff --git a/test/specs/commonmark/commonmark-spec.js b/test/specs/commonmark/commonmark-spec.js
index 280824f1c0..4205044586 100644
--- a/test/specs/commonmark/commonmark-spec.js
+++ b/test/specs/commonmark/commonmark-spec.js
@@ -155,7 +155,7 @@ describe('CommonMark 0.28 Fenced code blocks', function() {
   var section = 'Fenced code blocks';
 
   // var shouldPassButFails = [];
-  var shouldPassButFails = [93, 95, 96, 97, 101, 102, 106, 108, 111, 112, 113];
+  var shouldPassButFails = [93, 95, 96, 97, 101, 102, 106, 108, 112];
 
   var willNotBeAttemptedByCoreTeam = [];