diff --git a/packages/compose/README.md b/packages/compose/README.md
index 0166bc51d65aa..258b0c9311e73 100644
--- a/packages/compose/README.md
+++ b/packages/compose/README.md
@@ -168,7 +168,7 @@ _Parameters_
 
 -   _ref_ `import('react').RefObject<string | Element | NodeListOf<Element>>`: Reference with the element.
 -   _text_ `string|Function`: The text to copy.
--   _timeout_ `number`: Optional timeout to reset the returned state. 4 seconds by default.
+-   _timeout_ `[number]`: Optional timeout to reset the returned state. 4 seconds by default.
 
 _Returns_
 
diff --git a/packages/compose/src/hooks/use-copy-on-click/index.js b/packages/compose/src/hooks/use-copy-on-click/index.js
index 99c595be99a20..238e2bc35573d 100644
--- a/packages/compose/src/hooks/use-copy-on-click/index.js
+++ b/packages/compose/src/hooks/use-copy-on-click/index.js
@@ -17,7 +17,7 @@ import deprecated from '@wordpress/deprecated';
  *
  * @param {import('react').RefObject<string | Element | NodeListOf<Element>>} ref Reference with the element.
  * @param {string|Function} text The text to copy.
- * @param {number} timeout Optional timeout to reset the returned
+ * @param {number} [timeout] Optional timeout to reset the returned
  *                                  state. 4 seconds by default.
  *
  * @return {boolean} Whether or not the text has been copied. Resets after the