diff --git a/docs/en/appendices/6-0-migration-guide.md b/docs/en/appendices/6-0-migration-guide.md
index 271a548a25..6832c801e6 100644
--- a/docs/en/appendices/6-0-migration-guide.md
+++ b/docs/en/appendices/6-0-migration-guide.md
@@ -120,6 +120,10 @@ Some properties have also been renamed to better reflect their purpose. These ar
   `binary` columns to `varbinary`. The `fixed` option is no longer used;
   `TableSchemaInterface::TYPE_VARBINARY` is available for the new type.
 
+### Error
+
+- `Debugger::outputMask()`, `setOutputMask()` have been removed.
+
 ### Http
 
 - Using `$request->getParam('?')` to get the query params is no longer possible.
diff --git a/docs/en/development/debugging.md b/docs/en/development/debugging.md
index 2209f9b8d8..0402924ddb 100644
--- a/docs/en/development/debugging.md
+++ b/docs/en/development/debugging.md
@@ -65,8 +65,6 @@ The following configuration options can be set in **config/app.php** to change h
   `Debugger::addEditor()` during your application bootstrap.
 - `Debugger.editorBasePath` The path that replaces `ROOT` when generating
   editor links.
-- `Debugger.outputMask` A mapping of `key` to `replacement` values that
-  `Debugger` should replace in dumped data and logs generated by `Debugger`.
 
 ::: info Added in version 5.3.0
 The `Debugger.editorBasePath` configure option was added.
@@ -105,22 +103,6 @@ object(Car) {
 }
 ```
 
-### Masking Data
-
-When dumping data with `Debugger` or rendering error pages, you may want to
-hide sensitive keys like passwords or API keys. In your **config/bootstrap.php**
-you can mask specific keys:
-
-```php
-Debugger::setOutputMask([
-    'password' => 'xxxxx',
-    'awsKey' => 'yyyyy',
-]);
-```
-
-As of 4.1.0 you can use the `Debugger.outputMask` configuration value to set
-output masks.
-
 ## Logging With Stack Traces
 
 `static` Cake\\Error\\Debugger::**log**(mixed $var, string|int $level = 'debug', int $maxDepth = 3): void