diff --git a/index.d.ts b/index.d.ts
index ced1559263..386c2cc0bb 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -23,10 +23,7 @@ export interface Action {
  * This is not part of `Action` itself to prevent users who are extending `Action.
  * @private
  */
-export interface AnyAction extends Action {
-  // Allows any extra properties to be defined in an action.
-  [extraProps: string]: any;
-}
+type AnyAction = any;
 
 
 /* reducers */