diff --git a/types/redux-immutable/index.d.ts b/types/redux-immutable/index.d.ts
index e712f663f0..3cb6e16a1d 100644
--- a/types/redux-immutable/index.d.ts
+++ b/types/redux-immutable/index.d.ts
@@ -12,4 +12,4 @@ import { Collection } from 'immutable';
 
 export declare function combineReducers<S, A extends Action, T>(reducers: ReducersMapObject<S, A>, getDefaultState?: () => Collection.Keyed<T, S>): Reducer<S, A>;
 export declare function combineReducers<S, A extends Action>(reducers: ReducersMapObject<S, A>, getDefaultState?: () => Collection.Indexed<S>): Reducer<S, A>;
-export declare function combineReducers<S>(reducers: ReducersMapObject<S>, getDefaultState?: () => Collection.Indexed<S>): Reducer<S>;
+export declare function combineReducers<S>(reducers: ReducersMapObject<S, any>, getDefaultState?: () => Collection.Indexed<S>): Reducer<S>;