diff --git a/core/language/en-GB/Docs/ModuleTypes.multids b/core/language/en-GB/Docs/ModuleTypes.multids
index 6f7f08d30..7d666e309 100644
--- a/core/language/en-GB/Docs/ModuleTypes.multids
+++ b/core/language/en-GB/Docs/ModuleTypes.multids
@@ -14,6 +14,7 @@ storyview: Story views customise the animation and behaviour of list widgets.
 tiddlerdeserializer: Converts different content types into tiddlers.
 tiddlerfield: Defines the behaviour of an individual tiddler field.
 tiddlermethod: Adds methods to the `$tw.Tiddler` prototype.
+upgrader: Applies upgrade processing to tiddlers during an upgrade/import.
 utils: Adds methods to `$tw.utils`.
 utils-node: Adds Node.js-specific methods to `$tw.utils`.
 widget: Widgets encapsulate DOM rendering and refreshing.