diff --git a/package.json b/package.json
index 54613c8a..bb5d8239 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "rrweb-snapshot",
-  "version": "1.1.1",
+  "version": "1.1.2",
   "description": "rrweb's component to take a snapshot of DOM, aka DOM serializer",
   "scripts": {
     "prepare": "npm run prepack",
diff --git a/typings/snapshot.d.ts b/typings/snapshot.d.ts
index 91bec1a9..0581feda 100644
--- a/typings/snapshot.d.ts
+++ b/typings/snapshot.d.ts
@@ -1,4 +1,4 @@
-import { serializedNodeWithId, INode, idNodeMap, MaskInputOptions, MaskTextFn, SlimDOMOptions } from './types';
+import { serializedNodeWithId, INode, idNodeMap, MaskInputOptions, SlimDOMOptions, MaskTextFn } from './types';
 export declare const IGNORED_NODE = -2;
 export declare function absoluteToStylesheet(cssText: string | null, href: string): string;
 export declare function absoluteToDoc(doc: Document, attributeValue: string): string;
@@ -15,7 +15,7 @@ export declare function serializeNodeWithId(n: Node | INode, options: {
     skipChild: boolean;
     inlineStylesheet: boolean;
     maskInputOptions?: MaskInputOptions;
-    maskTextFn?: MaskTextFn;
+    maskTextFn: MaskTextFn | undefined;
     slimDOMOptions: SlimDOMOptions;
     recordCanvas?: boolean;
     preserveWhiteSpace?: boolean;