diff --git a/docs/reference-guides/data/data-core-block-editor.md b/docs/reference-guides/data/data-core-block-editor.md
index 7eed5c8741288b..040a10f8f506c2 100644
--- a/docs/reference-guides/data/data-core-block-editor.md
+++ b/docs/reference-guides/data/data-core-block-editor.md
@@ -412,7 +412,7 @@ Returns all blocks that match a blockName. Results include nested blocks.
 _Parameters_
 
 -   _state_ `Object`: Global application state.
--   _blockName_ `?string`: Optional block name, if not specified, returns an empty array.
+-   _blockName_ `string[]`: Block name(s) for which clientIds are to be returned.
 
 _Returns_
 
diff --git a/packages/block-editor/src/store/selectors.js b/packages/block-editor/src/store/selectors.js
index d6d09b59106110..f06293dadf233c 100644
--- a/packages/block-editor/src/store/selectors.js
+++ b/packages/block-editor/src/store/selectors.js
@@ -334,8 +334,8 @@ export const getGlobalBlockCount = createSelector(
 /**
  * Returns all blocks that match a blockName. Results include nested blocks.
  *
- * @param {Object}  state     Global application state.
- * @param {?string} blockName Optional block name, if not specified, returns an empty array.
+ * @param {Object}   state     Global application state.
+ * @param {string[]} blockName Block name(s) for which clientIds are to be returned.
  *
  * @return {Array} Array of clientIds of blocks with name equal to blockName.
  */
@@ -362,8 +362,8 @@ export const getBlocksByName = createSelector(
  *
  * @deprecated
  *
- * @param {Object}  state     Global application state.
- * @param {?string} blockName Optional block name, if not specified, returns an empty array.
+ * @param {Object}   state     Global application state.
+ * @param {string[]} blockName Block name(s) for which clientIds are to be returned.
  *
  * @return {Array} Array of clientIds of blocks with name equal to blockName.
  */