diff --git a/README.md b/README.md
index a761c2c..dd4f4b8 100644
--- a/README.md
+++ b/README.md
@@ -1036,7 +1036,7 @@ class <class_name>:
 ### Slots
 **Mechanism that restricts objects to attributes listed in 'slots' and significantly reduces their memory footprint.**
 
-```
+```python
 class MyClassWithSlots:
     __slots__ = ['a']
     def __init__(self):
diff --git a/index.html b/index.html
index 8ece0e5..c6db986 100644
--- a/index.html
+++ b/index.html
@@ -976,7 +976,7 @@ Z = dataclasses.make_dataclass(<span class="hljs-string">'Z'</span>, [<span clas
 </ul>
 <h3 id="slots">Slots</h3>
 <p><strong>Mechanism that restricts objects to attributes listed in 'slots' and significantly reduces their memory footprint.</strong></p>
-<pre><code class="python hljs"><span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">MyClassWithSlots</span>:</span>
+<pre><code class="python language-python hljs"><span class="hljs-class"><span class="hljs-keyword">class</span> <span class="hljs-title">MyClassWithSlots</span>:</span>
     __slots__ = [<span class="hljs-string">'a'</span>]
     <span class="hljs-function"><span class="hljs-keyword">def</span> <span class="hljs-title">__init__</span><span class="hljs-params">(self)</span>:</span>
         self.a = <span class="hljs-number">1</span>