diff --git a/types/redux-state-sync/index.d.ts b/types/redux-state-sync/index.d.ts
index 329f56908b..755d354707 100644
--- a/types/redux-state-sync/index.d.ts
+++ b/types/redux-state-sync/index.d.ts
@@ -3,6 +3,7 @@
 // Definitions by: MU AOHUA <https://github.com/AOHUA>
 //                 AntonioMendez <https://github.com/AntonioMendez>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.4
 
 import { Store, Reducer, Middleware, AnyAction } from "redux";
 import BroadcastChannel from "broadcast-channel";
diff --git a/types/redux-state-sync/package.json b/types/redux-state-sync/package.json
new file mode 100644
index 0000000000..d39f9e8fc6
--- /dev/null
+++ b/types/redux-state-sync/package.json
@@ -0,0 +1,7 @@
+{
+  "private": true,
+  "dependencies": {
+    "broadcast-channel": "^2.1.8",
+    "redux": "^4.0.1"
+  }
+}
diff --git a/types/redux-state-sync/redux-state-sync-tests.ts b/types/redux-state-sync/redux-state-sync-tests.ts
index 17e73dd591..3f5e689675 100644
--- a/types/redux-state-sync/redux-state-sync-tests.ts
+++ b/types/redux-state-sync/redux-state-sync-tests.ts
@@ -6,19 +6,17 @@ interface TestState {
     b: string;
     c: string;
 }
-const middlewares = [
-    createStateSyncMiddleware({
+const middleware = createStateSyncMiddleware({
         channel: 'test',
         predicate: (type) => true,
         blacklist: [],
         whitelist: [],
         broadcastChannelOption: {}
-    }),
-];
+    });
 
 function rootReducer(state: TestState, action: Action): TestState {
     return state;
 }
 
-const store = createStore(withReduxStateSync(rootReducer), ['test'], ...applyMiddleware(middlewares));
+const store = createStore(withReduxStateSync(rootReducer), ['test'], applyMiddleware(middleware));
 initStateWithPrevTab(store);