diff --git a/README.md b/README.md
index 996d1ec..2b9d359 100644
--- a/README.md
+++ b/README.md
@@ -289,6 +289,7 @@ True
 | fractions.Fraction |          |   yes    | yes  |   yes   |  yes   |
 | float              |          |          | yes  |   yes   |  yes   |
 | complex            |          |          |      |   yes   |  yes   |
+| decimal.Decimal    |          |          |      |         |  yes   |
 +--------------------+----------+----------+------+---------+--------+
 ```
 
diff --git a/index.html b/index.html
index d4b3be0..6d8be81 100644
--- a/index.html
+++ b/index.html
@@ -411,6 +411,7 @@ to_exclusive   = <range>.stop
 | fractions.Fraction |          |   yes    | yes  |   yes   |  yes   |
 | float              |          |          | yes  |   yes   |  yes   |
 | complex            |          |          |      |   yes   |  yes   |
+| decimal.Decimal    |          |          |      |         |  yes   |
 +--------------------+----------+----------+------+---------+--------+
 </code></pre>
 <div><h2 id="string"><a href="#string" name="string">#</a>String</h2><pre><code class="python language-python hljs">&lt;str&gt;  = &lt;str&gt;.strip()                       <span class="hljs-comment"># Strips all whitespace characters from both ends.</span>
diff --git a/web/script_2.js b/web/script_2.js
index 94d18ad..cfc9939 100644
--- a/web/script_2.js
+++ b/web/script_2.js
@@ -59,6 +59,7 @@ const DIAGRAM_4_B =
   '┃ fractions.Fraction │          │    ✓     │  ✓   │    ✓    │   ✓    ┃\n' +
   '┃ float              │          │          │  ✓   │    ✓    │   ✓    ┃\n' +
   '┃ complex            │          │          │      │    ✓    │   ✓    ┃\n' +
+  '┃ decimal.Decimal    │          │          │      │         │   ✓    ┃\n' +
   '┗━━━━━━━━━━━━━━━━━━━━┷━━━━━━━━━━┷━━━━━━━━━━┷━━━━━━┷━━━━━━━━━┷━━━━━━━━┛\n';
 
 const DIAGRAM_5_A =