diff --git a/dist/purify.cjs.d.ts b/dist/purify.cjs.d.ts
index faf4ac23..ef602d9f 100644
--- a/dist/purify.cjs.d.ts
+++ b/dist/purify.cjs.d.ts
@@ -206,9 +206,9 @@ declare const _default: DOMPurify;
 
 interface DOMPurify {
     /**
-     * Creates a DOMPurify instance using the given window-like object.
+     * Creates a DOMPurify instance using the given window-like object. Defaults to `window`.
      */
-    (root: WindowLike): DOMPurify;
+    (root?: WindowLike): DOMPurify;
     /**
      * Version label, exposed for easier checks
      * if DOMPurify is up to date or not
diff --git a/dist/purify.es.d.mts b/dist/purify.es.d.mts
index 4cb7625b..62f7f7f2 100644
--- a/dist/purify.es.d.mts
+++ b/dist/purify.es.d.mts
@@ -206,9 +206,9 @@ declare const _default: DOMPurify;
 
 interface DOMPurify {
     /**
-     * Creates a DOMPurify instance using the given window-like object.
+     * Creates a DOMPurify instance using the given window-like object. Defaults to `window`.
      */
-    (root: WindowLike): DOMPurify;
+    (root?: WindowLike): DOMPurify;
     /**
      * Version label, exposed for easier checks
      * if DOMPurify is up to date or not
diff --git a/src/purify.ts b/src/purify.ts
index f85aa148..4143aa27 100644
--- a/src/purify.ts
+++ b/src/purify.ts
@@ -1679,9 +1679,9 @@ export default createDOMPurify();
 
 export interface DOMPurify {
   /**
-   * Creates a DOMPurify instance using the given window-like object.
+   * Creates a DOMPurify instance using the given window-like object. Defaults to `window`.
    */
-  (root: WindowLike): DOMPurify;
+  (root?: WindowLike): DOMPurify;
 
   /**
    * Version label, exposed for easier checks