diff --git a/index.d.ts b/index.d.ts
index b2ab84e..caa264c 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -226,7 +226,7 @@ export interface Options {
 	//=> 'http://sindresorhus.com/foo'
 	```
 	*/
-	readonly removeDirectoryIndex?: ReadonlyArray<RegExp | string>;
+	readonly removeDirectoryIndex?: boolean | ReadonlyArray<RegExp | string>;
 
 	/**
 	Sorts the query parameters alphabetically by key.
diff --git a/readme.md b/readme.md
index b9f8bd5..fea18e8 100644
--- a/readme.md
+++ b/readme.md
@@ -242,7 +242,6 @@ normalizeUrl('https://sindresorhus.com/', {removeSingleSlash: false});
 //=> 'https://sindresorhus.com/'
 ```
 
-
 ##### removeDirectoryIndex
 
 Type: `boolean | Array<RegExp | string>`\