diff --git a/types/iframe-resizer/index.d.ts b/types/iframe-resizer/index.d.ts
index 9c6f7e80ba..8d65629da6 100644
--- a/types/iframe-resizer/index.d.ts
+++ b/types/iframe-resizer/index.d.ts
@@ -260,7 +260,7 @@ export interface IFrameResizedData {
 // tslint:disable-next-line:interface-name
 export interface IFrameMessageData {
   iframe: IFrameComponent;
-  message: string;
+  message: any;
 }
 
 // tslint:disable-next-line:interface-name