diff --git a/packages/redux-devtools-extension/src/developmentOnly.ts b/packages/redux-devtools-extension/src/developmentOnly.ts
index 61c9502f..4fec0ed1 100644
--- a/packages/redux-devtools-extension/src/developmentOnly.ts
+++ b/packages/redux-devtools-extension/src/developmentOnly.ts
@@ -15,18 +15,16 @@ declare const process: {
 
 function extensionComposeStub(
   config: Config,
-): <StoreEnhancers extends readonly StoreEnhancer<unknown>[]>(
+): <StoreEnhancers extends readonly StoreEnhancer[]>(
   ...funcs: StoreEnhancers
 ) => StoreEnhancer<InferComposedStoreExt<StoreEnhancers>>;
-function extensionComposeStub<
-  StoreEnhancers extends readonly StoreEnhancer<unknown>[],
->(
+function extensionComposeStub<StoreEnhancers extends readonly StoreEnhancer[]>(
   ...funcs: StoreEnhancers
 ): StoreEnhancer<InferComposedStoreExt<StoreEnhancers>>;
-function extensionComposeStub(...funcs: [Config] | StoreEnhancer<unknown>[]) {
+function extensionComposeStub(...funcs: [Config] | StoreEnhancer[]) {
   if (funcs.length === 0) return undefined;
   if (typeof funcs[0] === 'object') return compose;
-  return compose(...(funcs as StoreEnhancer<unknown>[]));
+  return compose(...(funcs as StoreEnhancer[]));
 }
 
 export const composeWithDevTools: ReduxDevtoolsExtensionCompose =
diff --git a/packages/redux-devtools-extension/src/index.ts b/packages/redux-devtools-extension/src/index.ts
index 86293b55..366b9e21 100644
--- a/packages/redux-devtools-extension/src/index.ts
+++ b/packages/redux-devtools-extension/src/index.ts
@@ -235,15 +235,16 @@ export type InferComposedStoreExt<StoreEnhancers> = StoreEnhancers extends [
   ? HeadStoreEnhancer extends StoreEnhancer<infer StoreExt>
     ? StoreExt & InferComposedStoreExt<RestStoreEnhancers>
     : never
-  : unknown;
+  : // eslint-disable-next-line @typescript-eslint/no-empty-object-type
+    {};
 
 export interface ReduxDevtoolsExtensionCompose {
   (
     config: Config,
-  ): <StoreEnhancers extends readonly StoreEnhancer<unknown>[]>(
+  ): <StoreEnhancers extends readonly StoreEnhancer[]>(
     ...funcs: StoreEnhancers
   ) => StoreEnhancer<InferComposedStoreExt<StoreEnhancers>>;
-  <StoreEnhancers extends readonly StoreEnhancer<unknown>[]>(
+  <StoreEnhancers extends readonly StoreEnhancer[]>(
     ...funcs: StoreEnhancers
   ): StoreEnhancer<InferComposedStoreExt<StoreEnhancers>>;
 }
@@ -257,18 +258,16 @@ declare global {
 
 function extensionComposeStub(
   config: Config,
-): <StoreEnhancers extends readonly StoreEnhancer<unknown>[]>(
+): <StoreEnhancers extends readonly StoreEnhancer[]>(
   ...funcs: StoreEnhancers
 ) => StoreEnhancer<InferComposedStoreExt<StoreEnhancers>>;
-function extensionComposeStub<
-  StoreEnhancers extends readonly StoreEnhancer<unknown>[],
->(
+function extensionComposeStub<StoreEnhancers extends readonly StoreEnhancer[]>(
   ...funcs: StoreEnhancers
 ): StoreEnhancer<InferComposedStoreExt<StoreEnhancers>>;
-function extensionComposeStub(...funcs: [Config] | StoreEnhancer<unknown>[]) {
+function extensionComposeStub(...funcs: [Config] | StoreEnhancer[]) {
   if (funcs.length === 0) return undefined;
   if (typeof funcs[0] === 'object') return compose;
-  return compose(...(funcs as StoreEnhancer<unknown>[]));
+  return compose(...(funcs as StoreEnhancer[]));
 }
 
 export const composeWithDevTools: ReduxDevtoolsExtensionCompose =
diff --git a/packages/redux-devtools-extension/src/logOnly.ts b/packages/redux-devtools-extension/src/logOnly.ts
index 67b54382..349ed720 100644
--- a/packages/redux-devtools-extension/src/logOnly.ts
+++ b/packages/redux-devtools-extension/src/logOnly.ts
@@ -1,12 +1,5 @@
-import assign from './utils/assign';
 import { compose } from 'redux';
-import type {
-  Action,
-  Dispatch,
-  PreloadedState,
-  Reducer,
-  StoreEnhancer,
-} from 'redux';
+import type { Action, Dispatch, Reducer, StoreEnhancer } from 'redux';
 import type { Config, EnhancerOptions, InferComposedStoreExt } from './index';
 
 function enhancer(options?: EnhancerOptions): StoreEnhancer {
@@ -17,9 +10,9 @@ function enhancer(options?: EnhancerOptions): StoreEnhancer {
   if (config.latency === undefined) config.latency = 500;
 
   return function (createStore) {
-    return function <S, A extends Action<string>>(
-      reducer: Reducer<S, A>,
-      preloadedState: PreloadedState<S> | undefined,
+    return function <S, A extends Action<string>, PreloadedState>(
+      reducer: Reducer<S, A, PreloadedState>,
+      preloadedState?: PreloadedState | undefined,
     ) {
       const store = createStore(reducer, preloadedState);
       const origDispatch = store.dispatch;
@@ -33,35 +26,32 @@ function enhancer(options?: EnhancerOptions): StoreEnhancer {
         return r;
       };
 
-      if (Object.assign) return Object.assign(store, { dispatch: dispatch });
-      return assign(store, 'dispatch', dispatch);
+      return Object.assign(store, { dispatch: dispatch });
     };
   };
 }
 
 function composeWithEnhancer(config?: EnhancerOptions) {
-  return function (...funcs: StoreEnhancer<unknown>[]) {
+  return function (...funcs: StoreEnhancer[]) {
     return compose(compose(...funcs), enhancer(config));
   };
 }
 
 export function composeWithDevTools(
   config: Config,
-): <StoreEnhancers extends readonly StoreEnhancer<unknown>[]>(
+): <StoreEnhancers extends readonly StoreEnhancer[]>(
   ...funcs: StoreEnhancers
 ) => StoreEnhancer<InferComposedStoreExt<StoreEnhancers>>;
 export function composeWithDevTools<
-  StoreEnhancers extends readonly StoreEnhancer<unknown>[],
+  StoreEnhancers extends readonly StoreEnhancer[],
 >(
   ...funcs: StoreEnhancers
 ): StoreEnhancer<InferComposedStoreExt<StoreEnhancers>>;
-export function composeWithDevTools(
-  ...funcs: [Config] | StoreEnhancer<unknown>[]
-) {
+export function composeWithDevTools(...funcs: [Config] | StoreEnhancer[]) {
   if (typeof window !== 'undefined' && window.__REDUX_DEVTOOLS_EXTENSION__) {
     if (funcs.length === 0) return enhancer();
     if (typeof funcs[0] === 'object') return composeWithEnhancer(funcs[0]);
-    return composeWithEnhancer()(...(funcs as StoreEnhancer<unknown>[]));
+    return composeWithEnhancer()(...(funcs as StoreEnhancer[]));
   }
 
   if (funcs.length === 0) return undefined;
diff --git a/packages/redux-devtools-extension/src/logOnlyInProduction.ts b/packages/redux-devtools-extension/src/logOnlyInProduction.ts
index 59ccf317..cdc06c55 100644
--- a/packages/redux-devtools-extension/src/logOnlyInProduction.ts
+++ b/packages/redux-devtools-extension/src/logOnlyInProduction.ts
@@ -16,18 +16,16 @@ declare const process: {
 
 function extensionComposeStub(
   config: Config,
-): <StoreEnhancers extends readonly StoreEnhancer<unknown>[]>(
+): <StoreEnhancers extends readonly StoreEnhancer[]>(
   ...funcs: StoreEnhancers
 ) => StoreEnhancer<InferComposedStoreExt<StoreEnhancers>>;
-function extensionComposeStub<
-  StoreEnhancers extends readonly StoreEnhancer<unknown>[],
->(
+function extensionComposeStub<StoreEnhancers extends readonly StoreEnhancer[]>(
   ...funcs: StoreEnhancers
 ): StoreEnhancer<InferComposedStoreExt<StoreEnhancers>>;
-function extensionComposeStub(...funcs: [Config] | StoreEnhancer<unknown>[]) {
+function extensionComposeStub(...funcs: [Config] | StoreEnhancer[]) {
   if (funcs.length === 0) return undefined;
   if (typeof funcs[0] === 'object') return compose;
-  return compose(...(funcs as StoreEnhancer<unknown>[]));
+  return compose(...(funcs as StoreEnhancer[]));
 }
 
 export const composeWithDevTools: ReduxDevtoolsExtensionCompose =
diff --git a/packages/redux-devtools-extension/src/utils/assign.ts b/packages/redux-devtools-extension/src/utils/assign.ts
deleted file mode 100644
index b453fb6e..00000000
--- a/packages/redux-devtools-extension/src/utils/assign.ts
+++ /dev/null
@@ -1,26 +0,0 @@
-const objectKeys =
-  Object.keys ||
-  function (obj) {
-    const keys = [];
-    for (const key in obj) {
-      if ({}.hasOwnProperty.call(obj, key)) keys.push(key);
-    }
-    return keys;
-  };
-
-export default function assign<T extends object, K extends keyof T>(
-  obj: T,
-  newKey: K,
-  newValue: T[K],
-): T {
-  const keys = objectKeys(obj);
-  const copy: T = {} as T;
-
-  for (let i = 0, l = keys.length; i < l; i++) {
-    const key = keys[i];
-    copy[key as keyof T] = obj[key as keyof T];
-  }
-
-  copy[newKey] = newValue;
-  return copy;
-}