diff --git a/components/cache/adapters/pdo_adapter.rst b/components/cache/adapters/pdo_adapter.rst
index 62d4dcc90aa..4920520196f 100644
--- a/components/cache/adapters/pdo_adapter.rst
+++ b/components/cache/adapters/pdo_adapter.rst
@@ -53,3 +53,4 @@ your code.
     class instance), the connection will be lazy-loaded when needed.
 
 .. _`DSN`: https://php.net/manual/pdo.drivers.php
+.. _`Data Source Name (DSN)`: https://en.wikipedia.org/wiki/Data_source_name