diff --git a/docs/en/reference/basic-mapping.rst b/docs/en/reference/basic-mapping.rst
index fbbe373de..82000d9c3 100644
--- a/docs/en/reference/basic-mapping.rst
+++ b/docs/en/reference/basic-mapping.rst
@@ -151,7 +151,7 @@ Here is a quick overview of the built-in mapping types:
 -  ``string``
 -  ``timestamp``
 
-You can read more about the available MongoDB types on `php.net <https://www.php.net/manual/en/book.bson.php>`_.
+You can read more about the available MongoDB types on `php.net <https://www.php.net/manual/en/mongodb.bson.php>`_.
 
 .. note::