diff --git a/src/story.ts b/src/story.ts
index 11e362e..891c8b8 100644
--- a/src/story.ts
+++ b/src/story.ts
@@ -122,7 +122,7 @@ export interface InputType {
   /**
    * @see https://storybook.js.org/docs/api/arg-types#mapping
    */
-  mapping?: { [key: string]: { [option: string]: any } };
+  mapping?: { [key: string]: any };
   /**
    * @see https://storybook.js.org/docs/api/arg-types#name
    */