diff --git a/README.md b/README.md
index a034885..d30c9f5 100644
--- a/README.md
+++ b/README.md
@@ -214,7 +214,6 @@ The `createWrapper` function accepts `makeStore` as its first argument. The `mak
 
 `createWrapper` also optionally accepts a config object as a second parameter:
 
-- `storeKey` (optional, string) : the key used on `window` to persist the store on the client
 - `debug` (optional, boolean) : enable debug logging
 - `serializeState` and `deserializeState`: custom functions for serializing and deserializing the redux state, see
     [Custom serialization and deserialization](#custom-serialization-and-deserialization).
diff --git a/packages/wrapper/src/index.tsx b/packages/wrapper/src/index.tsx
index ada87b6..9ebf216 100644
--- a/packages/wrapper/src/index.tsx
+++ b/packages/wrapper/src/index.tsx
@@ -12,7 +12,6 @@ import {
 } from 'next';
 
 export const HYDRATE = '__NEXT_REDUX_WRAPPER_HYDRATE__';
-export const STOREKEY = '__NEXT_REDUX_WRAPPER_STORE__';
 
 const getIsServer = () => typeof window === 'undefined';
 
@@ -22,19 +21,16 @@ const getDeserializedState = <S extends Store>(initialState: any, {deserializeSt
 const getSerializedState = <S extends Store>(state: any, {serializeState}: Config<S> = {}) =>
     serializeState ? serializeState(state) : state;
 
-const getStoreKey = <S extends Store>({storeKey}: Config<S> = {}) => storeKey || STOREKEY;
-
 export declare type MakeStore<S extends Store> = (context: Context) => S;
 
 export interface InitStoreOptions<S extends Store> {
     makeStore: MakeStore<S>;
     context: Context;
-    config: Config<S>;
 }
 
-const initStore = <S extends Store>({makeStore, context, config}: InitStoreOptions<S>): S => {
-    const storeKey = getStoreKey(config);
+let store: any;
 
+const initStore = <S extends Store>({makeStore, context}: InitStoreOptions<S>): S => {
     const createStore = () => makeStore(context);
 
     if (getIsServer()) {
@@ -48,15 +44,16 @@ const initStore = <S extends Store>({makeStore, context, config}: InitStoreOptio
             if (!req.__nextReduxWrapperStore) req.__nextReduxWrapperStore = createStore();
             return req.__nextReduxWrapperStore;
         }
+
         return createStore();
     }
 
     // Memoize store if client
-    if (!(storeKey in window)) {
-        (window as any)[storeKey] = createStore();
+    if (!store) {
+        store = createStore();
     }
 
-    return (window as any)[storeKey];
+    return store;
 };
 
 export const createWrapper = <S extends Store>(makeStore: MakeStore<S>, config: Config<S> = {}) => {
@@ -67,7 +64,7 @@ export const createWrapper = <S extends Store>(makeStore: MakeStore<S>, config:
         callback: Callback<S, any>;
         context: any;
     }): Promise<WrapperProps> => {
-        const store = initStore({context, makeStore, config});
+        const store = initStore({context, makeStore});
 
         if (config.debug) console.log(`1. getProps created store with state`, store.getState());
 
@@ -141,7 +138,7 @@ export const createWrapper = <S extends Store>(makeStore: MakeStore<S>, config:
                 const initialStateFromGSPorGSSR = props?.pageProps?.initialState;
 
                 if (!this.store) {
-                    this.store = initStore({makeStore, config, context});
+                    this.store = initStore({makeStore, context});
 
                     if (config.debug)
                         console.log('4. WrappedApp created new store with', displayName, {
@@ -232,7 +229,6 @@ export type Context = NextPageContext | AppContext | GetStaticPropsContext | Get
 export interface Config<S extends Store> {
     serializeState?: (state: ReturnType<S['getState']>) => any;
     deserializeState?: (state: any) => ReturnType<S['getState']>;
-    storeKey?: string;
     debug?: boolean;
 }
 
diff --git a/packages/wrapper/tests/client.spec.tsx b/packages/wrapper/tests/client.spec.tsx
index 718ecc4..a8d2112 100644
--- a/packages/wrapper/tests/client.spec.tsx
+++ b/packages/wrapper/tests/client.spec.tsx
@@ -7,23 +7,19 @@ import {DummyComponent, wrapper, child, makeStore} from './testlib';
 import {createWrapper} from '../src';
 import {Store} from 'redux';
 
-const w: {testStoreKey?: Store} = window as any;
+let store: Store;
 
 const defaultState = {reduxStatus: 'init'};
 
 describe('client integration', () => {
-    afterEach(() => {
-        delete w.testStoreKey;
-    });
-
     describe('existing store is taken from window', () => {
         beforeEach(() => {
-            w.testStoreKey = makeStore();
+            store = makeStore();
         });
 
         test('withRedux', async () => {
             const WrappedPage: any = wrapper.withRedux(DummyComponent);
-            expect(child(<WrappedPage initialState={w.testStoreKey?.getState()} />)).toEqual(
+            expect(child(<WrappedPage initialState={store.getState()} />)).toEqual(
                 '{"props":{},"state":{"reduxStatus":"init"}}',
             );
         });
@@ -38,11 +34,11 @@ describe('client integration', () => {
         });
     });
 
-    test('store is available in window when created', async () => {
-        const wrapper = createWrapper(makeStore, {storeKey: 'testStoreKey'});
+    test('store is available when calling getInitialProps client-side', async () => {
+        const wrapper = createWrapper(makeStore);
         const Page = () => null;
         Page.getInitialProps = wrapper.getInitialPageProps(store => () => null);
         await wrapper.withRedux(Page)?.getInitialProps({} as any);
-        expect(w.testStoreKey?.getState()).toEqual(defaultState);
+        expect(store.getState()).toEqual(defaultState);
     });
 });
diff --git a/packages/wrapper/tests/testlib.tsx b/packages/wrapper/tests/testlib.tsx
index cf7c15f..253adfa 100644
--- a/packages/wrapper/tests/testlib.tsx
+++ b/packages/wrapper/tests/testlib.tsx
@@ -24,7 +24,7 @@ export const reducer = (state: State = {reduxStatus: 'init'}, action: AnyAction)
 
 export const makeStore = () => createStore(reducer, undefined, applyMiddleware(promiseMiddleware));
 
-export const wrapper = createWrapper(makeStore, {storeKey: 'testStoreKey'});
+export const wrapper = createWrapper(makeStore);
 
 export const DummyComponent = (props: any) => {
     const state = useSelector((state: State) => state);