diff --git a/src/apiTypes.ts b/src/apiTypes.ts
index 9285b541d..8dbb8db85 100644
--- a/src/apiTypes.ts
+++ b/src/apiTypes.ts
@@ -2,7 +2,7 @@
  * Note: this file should import all other files for type discovery and declaration merging
  */
 import { PatchQueryResultThunk, QueryApi, UpdateQueryResultThunk } from './buildThunks';
-import { AnyAction, Middleware, Reducer, ThunkDispatch } from '@reduxjs/toolkit';
+import { AnyAction, Middleware, Reducer, ThunkDispatch, ThunkAction } from '@reduxjs/toolkit';
 import { PrefetchOptions } from './buildHooks';
 import {
   EndpointDefinitions,
@@ -12,10 +12,10 @@ import {
   MutationDefinition,
 } from './endpointDefinitions';
 import { CombinedState, QueryKeys, QueryStatePhantomType, RootState } from './apiState';
-import { InternalActions } from './index';
 import { UnionToIntersection } from './tsHelpers';
 import { TS41Hooks } from './ts41Types';
 import './buildSelectors';
+import { SliceActions } from './buildSlice';
 
 type UnwrapPromise<T> = T extends PromiseLike<infer V> ? V : T;
 type MaybePromise<T> = T | PromiseLike<T>;
@@ -110,3 +110,7 @@ export type ApiWithInjectedEndpoints<
   Omit<Injections, 'endpoints'> & {
     endpoints: ApiDefinition['endpoints'] & Partial<UnionToIntersection<Injections[number]['endpoints']>>;
   };
+
+export type InternalActions = SliceActions & {
+  prefetchThunk: (endpointName: any, arg: any, options: PrefetchOptions) => ThunkAction<void, any, any, AnyAction>;
+};
diff --git a/src/buildActionMaps.ts b/src/buildActionMaps.ts
index 31342b62a..2df4d4b1d 100644
--- a/src/buildActionMaps.ts
+++ b/src/buildActionMaps.ts
@@ -2,7 +2,7 @@ import { EndpointDefinitions, QueryDefinition, MutationDefinition, QueryArgFrom
 import type { QueryThunkArg, MutationThunkArg } from './buildThunks';
 import { AnyAction, AsyncThunk, ThunkAction } from '@reduxjs/toolkit';
 import { MutationSubState, QueryStatus, QuerySubState, SubscriptionOptions } from './apiState';
-import { InternalSerializeQueryArgs } from '.';
+import { InternalSerializeQueryArgs } from './defaultSerializeQueryArgs';
 import { Api, ApiEndpointMutation, ApiEndpointQuery } from './apiTypes';
 
 declare module './apiTypes' {
diff --git a/src/buildSelectors.ts b/src/buildSelectors.ts
index 3a40be644..1083ac3dd 100644
--- a/src/buildSelectors.ts
+++ b/src/buildSelectors.ts
@@ -16,7 +16,7 @@ import {
   ReducerPathFrom,
 } from './endpointDefinitions';
 import type { InternalState } from './buildSlice';
-import { InternalSerializeQueryArgs } from '.';
+import { InternalSerializeQueryArgs } from './defaultSerializeQueryArgs';
 
 export const skipSelector = Symbol('skip selector');
 
diff --git a/src/buildThunks.ts b/src/buildThunks.ts
index db91661d3..b04319580 100644
--- a/src/buildThunks.ts
+++ b/src/buildThunks.ts
@@ -1,4 +1,4 @@
-import { InternalSerializeQueryArgs } from '.';
+import { InternalSerializeQueryArgs } from './defaultSerializeQueryArgs';
 import { Api, ApiEndpointQuery, BaseQueryFn, BaseQueryArg, BaseQueryError } from './apiTypes';
 import { InternalRootState, QueryKeys, QueryStatus, QuerySubstateIdentifier } from './apiState';
 import { StartQueryActionCreatorOptions } from './buildActionMaps';
diff --git a/src/defaultSerializeQueryArgs.ts b/src/defaultSerializeQueryArgs.ts
new file mode 100644
index 000000000..31e6c8990
--- /dev/null
+++ b/src/defaultSerializeQueryArgs.ts
@@ -0,0 +1,18 @@
+import { QueryCacheKey } from './apiState';
+
+export const defaultSerializeQueryArgs: SerializeQueryArgs<any> = ({ endpoint, queryArgs }) => {
+  // Sort the object keys before stringifying, to prevent useQuery({ a: 1, b: 2 }) having a different cache key than  useQuery({ b: 2, a: 1 })
+  return `${endpoint}(${JSON.stringify(queryArgs, Object.keys(queryArgs || {}).sort())})`;
+};
+
+export type SerializeQueryArgs<InternalQueryArgs> = (_: {
+  queryArgs: any;
+  internalQueryArgs: InternalQueryArgs;
+  endpoint: string;
+}) => string;
+
+export type InternalSerializeQueryArgs<InternalQueryArgs> = (_: {
+  queryArgs: any;
+  internalQueryArgs: InternalQueryArgs;
+  endpoint: string;
+}) => QueryCacheKey;
diff --git a/src/index.ts b/src/index.ts
index a552de7b6..45a449276 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,47 +1,30 @@
-import { buildThunks } from './buildThunks';
-import type { AnyAction, Reducer, ThunkAction } from '@reduxjs/toolkit';
-import { buildSlice, SliceActions } from './buildSlice';
+import type { AnyAction, Reducer } from '@reduxjs/toolkit';
+import type { CombinedState, QueryStatePhantomType } from './apiState';
+import { Api, BaseQueryArg, BaseQueryFn } from './apiTypes';
 import { buildActionMaps } from './buildActionMaps';
-import { buildSelectors } from './buildSelectors';
-import { buildHooks, PrefetchOptions } from './buildHooks';
+import { buildHooks } from './buildHooks';
 import { buildMiddleware } from './buildMiddleware';
+import { buildSelectors } from './buildSelectors';
+import { buildSlice } from './buildSlice';
+import { buildThunks } from './buildThunks';
+import { defaultSerializeQueryArgs, InternalSerializeQueryArgs, SerializeQueryArgs } from './defaultSerializeQueryArgs';
 import {
-  EndpointDefinitions,
-  EndpointBuilder,
+  AssertEntityTypes,
   DefinitionType,
-  isQueryDefinition,
+  EndpointBuilder,
+  EndpointDefinitions,
   isMutationDefinition,
-  AssertEntityTypes,
+  isQueryDefinition,
 } from './endpointDefinitions';
-import type { CombinedState, QueryCacheKey, QueryStatePhantomType } from './apiState';
 import { assertCast } from './tsHelpers';
-import { Api, BaseQueryArg, BaseQueryFn } from './apiTypes';
-export { Api, ApiWithInjectedEndpoints, BaseQueryFn, BaseQueryEnhancer } from './apiTypes';
-export { fetchBaseQuery, FetchBaseQueryError } from './fetchBaseQuery';
+import { capitalize, IS_DEV } from './utils';
+export { ApiProvider } from './ApiProvider';
 export { QueryStatus } from './apiState';
+export type { Api, ApiWithInjectedEndpoints, BaseQueryEnhancer, BaseQueryFn } from './apiTypes';
+export { fetchBaseQuery } from './fetchBaseQuery';
+export type { FetchBaseQueryError } from './fetchBaseQuery';
 export { retry } from './retry';
 
-export { ApiProvider } from './ApiProvider';
-
-export type SerializeQueryArgs<InternalQueryArgs> = (_: {
-  queryArgs: any;
-  internalQueryArgs: InternalQueryArgs;
-  endpoint: string;
-}) => string;
-
-export type InternalSerializeQueryArgs<InternalQueryArgs> = (_: {
-  queryArgs: any;
-  internalQueryArgs: InternalQueryArgs;
-  endpoint: string;
-}) => QueryCacheKey;
-
-const defaultSerializeQueryArgs: SerializeQueryArgs<any> = ({ endpoint, queryArgs }) => {
-  // Sort the object keys before stringifying, to prevent useQuery({ a: 1, b: 2 }) having a different cache key than  useQuery({ b: 2, a: 1 })
-  return `${endpoint}(${JSON.stringify(queryArgs, Object.keys(queryArgs || {}).sort())})`;
-};
-
-const IS_DEV = () => typeof process !== 'undefined' && process.env.NODE_ENV === 'development';
-
 export function createApi<
   BaseQuery extends BaseQueryFn,
   Definitions extends EndpointDefinitions,
@@ -205,11 +188,3 @@ export function createApi<
 
   return api.injectEndpoints({ endpoints });
 }
-
-export type InternalActions = SliceActions & {
-  prefetchThunk: (endpointName: any, arg: any, options: PrefetchOptions) => ThunkAction<void, any, any, AnyAction>;
-};
-
-function capitalize(str: string) {
-  return str.replace(str[0], str[0].toUpperCase());
-}
diff --git a/src/utils/capitalize.ts b/src/utils/capitalize.ts
new file mode 100644
index 000000000..b7aa41b38
--- /dev/null
+++ b/src/utils/capitalize.ts
@@ -0,0 +1,3 @@
+export function capitalize(str: string) {
+  return str.replace(str[0], str[0].toUpperCase());
+}
diff --git a/src/utils/index.ts b/src/utils/index.ts
index 343a7f19c..af8b0856b 100644
--- a/src/utils/index.ts
+++ b/src/utils/index.ts
@@ -4,3 +4,5 @@ export * from './joinUrls';
 export * from './flatten';
 export * from './shallowEqual';
 export * from './useShallowStableValue';
+export * from './capitalize';
+export * from './isDev';
diff --git a/src/utils/isDev.ts b/src/utils/isDev.ts
new file mode 100644
index 000000000..16e49bb89
--- /dev/null
+++ b/src/utils/isDev.ts
@@ -0,0 +1 @@
+export const IS_DEV = () => typeof process !== 'undefined' && process.env.NODE_ENV === 'development';
diff --git a/test/matchers.test.tsx b/test/matchers.test.tsx
index 3d4f48c28..f63e17c88 100644
--- a/test/matchers.test.tsx
+++ b/test/matchers.test.tsx
@@ -130,6 +130,7 @@ test('inferred types', () => {
         })
         .addMatcher(api.endpoints.querySuccess.matchFulfilled, (state, action) => {
           expectExactType({} as ResultType)(action.payload.result);
+          expectExactType(0 as number)(action.payload.fulfilledTimeStamp);
           // @ts-expect-error
           console.log(action.error);
           expectExactType({} as ArgType)(action.meta.arg.originalArgs);