diff --git a/src/middleware.ts b/src/middleware.ts
index d44d9a921c..240a60a3f3 100644
--- a/src/middleware.ts
+++ b/src/middleware.ts
@@ -14,6 +14,15 @@ import {
 
 const DEVTOOLS = Symbol()
 
+type DevtoolsType = {
+  prefix: string
+  subscribe: (dispatch: any) => () => void
+  unsubscribe: () => void
+  send: (action: string, state: any) => void
+  init: (state: any) => void
+  error: (payload: any) => void
+}
+
 export const redux =
   <S extends State, A extends { type: unknown }>(
     reducer: (state: S, action: A) => S,
@@ -24,7 +33,7 @@ export const redux =
     get: GetState<S & { dispatch: (a: A) => A }>,
     api: StoreApi<S & { dispatch: (a: A) => A }> & {
       dispatch: (a: A) => A
-      devtools?: any
+      devtools?: DevtoolsType
     }
   ): S & { dispatch: (a: A) => A } => {
     api.dispatch = (action: A) => {
@@ -56,14 +65,12 @@ export const devtools =
     InnerCustomSetState extends NamedSet<S>,
     InnerCustomGetState extends GetState<S>,
     InnerCustomStoreApi extends StoreApi<S> & {
-      setState: NamedSet<S>
+      dispatch?: unknown
+      devtools?: DevtoolsType
     },
-    OuterCustomSetState extends InnerCustomSetState & SetState<S>,
+    OuterCustomSetState extends SetState<S>,
     OuterCustomGetState extends InnerCustomGetState,
-    OuterCustomStoreApi extends InnerCustomStoreApi & {
-      dispatch?: unknown
-      devtools: any
-    }
+    OuterCustomStoreApi extends InnerCustomStoreApi
   >(
     fn: (
       set: InnerCustomSetState,
@@ -110,7 +117,7 @@ export const devtools =
       ) {
         console.warn('Please install/enable Redux devtools extension')
       }
-      api.devtools = null
+      delete api.devtools
       return fn(
         set as unknown as InnerCustomSetState,
         get as InnerCustomGetState,
@@ -119,7 +126,7 @@ export const devtools =
     }
     const namedSet: NamedSet<S> = (state, replace, name) => {
       set(state, replace)
-      if (!api.dispatch) {
+      if (!api.dispatch && api.devtools) {
         api.devtools.send(api.devtools.prefix + (name || 'action'), get())
       }
     }
@@ -142,15 +149,15 @@ export const devtools =
         const newState = api.getState()
         if (state !== newState) {
           savedSetState(state, replace)
-          if (state !== (newState as any)[DEVTOOLS]) {
+          if (state !== (newState as any)[DEVTOOLS] && api.devtools) {
             api.devtools.send(api.devtools.prefix + 'setState', api.getState())
           }
         }
       }
       options = typeof options === 'string' ? { name: options } : options
-      api.devtools = extension.connect({ ...options })
-      api.devtools.prefix = options?.name ? `${options.name} > ` : ''
-      api.devtools.subscribe((message: any) => {
+      const connection = (api.devtools = extension.connect({ ...options }))
+      connection.prefix = options?.name ? `${options.name} > ` : ''
+      connection.subscribe((message: any) => {
         if (message.type === 'ACTION' && message.payload) {
           try {
             api.setState(JSON.parse(message.payload))
@@ -178,7 +185,7 @@ export const devtools =
           message.type === 'DISPATCH' &&
           message.payload?.type === 'COMMIT'
         ) {
-          api.devtools.init(api.getState())
+          connection.init(api.getState())
         } else if (
           message.type === 'DISPATCH' &&
           message.payload?.type === 'IMPORT_STATE'
@@ -192,16 +199,16 @@ export const devtools =
               const action = actions[index] || 'No action found'
 
               if (index === 0) {
-                api.devtools.init(state)
+                connection.init(state)
               } else {
                 savedSetState(state)
-                api.devtools.send(action, api.getState())
+                connection.send(action, api.getState())
               }
             }
           )
         }
       })
-      api.devtools.init(initialState)
+      connection.init(initialState)
     }
     return initialState
   }
@@ -305,42 +312,57 @@ export function subscribeWithSelector<
 }
 
 type Combine<T, U> = Omit<T, keyof U> & U
-export const combine =
-  <
-    PrimaryState extends State,
-    SecondaryState extends State,
-    OuterCustomSetState extends SetState<Combine<PrimaryState, SecondaryState>>,
-    OuterCustomGetState extends GetState<Combine<PrimaryState, SecondaryState>>,
-    OuterCustomStoreApi extends StoreApi<Combine<PrimaryState, SecondaryState>>,
-    InnerCustomSetState extends OuterCustomSetState extends NamedSet<
-      Combine<PrimaryState, SecondaryState>
-    >
-      ? NamedSet<PrimaryState>
-      : SetState<PrimaryState>,
-    InnerCustomGetState extends GetState<PrimaryState>,
-    InnerCustomStoreApi extends StoreApi<PrimaryState>
-  >(
-    initialState: PrimaryState,
-    create: (
-      set: InnerCustomSetState,
-      get: InnerCustomGetState,
-      api: InnerCustomStoreApi
-    ) => SecondaryState
-  ) =>
-  (
-    set: OuterCustomSetState,
-    get: OuterCustomGetState,
-    api: OuterCustomStoreApi
+
+export function combine<
+  PrimaryState extends State,
+  SecondaryState extends State
+>(
+  initialState: PrimaryState,
+  create: (
+    set: NamedSet<PrimaryState>,
+    get: GetState<PrimaryState>,
+    api: StoreApi<PrimaryState>
+  ) => SecondaryState
+): (
+  set: NamedSet<Combine<PrimaryState, SecondaryState>>,
+  get: GetState<Combine<PrimaryState, SecondaryState>>,
+  api: StoreApi<Combine<PrimaryState, SecondaryState>>
+) => Combine<PrimaryState, SecondaryState>
+
+export function combine<
+  PrimaryState extends State,
+  SecondaryState extends State
+>(
+  initialState: PrimaryState,
+  create: (
+    set: SetState<PrimaryState>,
+    get: GetState<PrimaryState>,
+    api: StoreApi<PrimaryState>
+  ) => SecondaryState
+): (
+  set: SetState<Combine<PrimaryState, SecondaryState>>,
+  get: GetState<Combine<PrimaryState, SecondaryState>>,
+  api: StoreApi<Combine<PrimaryState, SecondaryState>>
+) => Combine<PrimaryState, SecondaryState>
+
+export function combine<
+  PrimaryState extends State,
+  SecondaryState extends State
+>(
+  initialState: PrimaryState,
+  create: (
+    set: SetState<PrimaryState>,
+    get: GetState<PrimaryState>,
+    api: StoreApi<PrimaryState>
+  ) => SecondaryState
+) {
+  return (
+    set: SetState<Combine<PrimaryState, SecondaryState>>,
+    get: GetState<Combine<PrimaryState, SecondaryState>>,
+    api: StoreApi<Combine<PrimaryState, SecondaryState>>
   ) =>
-    Object.assign(
-      {},
-      initialState,
-      create(
-        set as unknown as InnerCustomSetState,
-        get as unknown as InnerCustomGetState,
-        api as unknown as InnerCustomStoreApi
-      )
-    ) as Combine<PrimaryState, SecondaryState>
+    Object.assign({}, initialState, create(set as any, get as any, api as any))
+}
 
 type DeepPartial<T extends Object> = {
   [P in keyof T]?: DeepPartial<T[P]>
diff --git a/tests/middlewareTypes.test.tsx b/tests/middlewareTypes.test.tsx
index 51659517c4..fa1c3db771 100644
--- a/tests/middlewareTypes.test.tsx
+++ b/tests/middlewareTypes.test.tsx
@@ -1,12 +1,6 @@
 import { produce } from 'immer'
 import type { Draft } from 'immer'
-import create, {
-  GetState,
-  State,
-  StateCreator,
-  StoreApi,
-  UseBoundStore,
-} from 'zustand'
+import create, { State, StateCreator, UseBoundStore } from 'zustand'
 import {
   NamedSet,
   combine,
@@ -20,12 +14,7 @@ type TImmerConfigFn<T extends State> = (
   partial: ((draft: Draft<T>) => void) | T,
   replace?: boolean
 ) => void
-type TImmerConfig<
-  T extends State,
-  CustomSetState = TImmerConfigFn<T>,
-  CustomGetState = GetState<T>,
-  CustomStoreApi extends StoreApi<T> = StoreApi<T>
-> = StateCreator<T, CustomSetState, CustomGetState, CustomStoreApi>
+type TImmerConfig<T extends State> = StateCreator<T, TImmerConfigFn<T>>
 
 interface ISelectors<T> {
   use: {
@@ -272,6 +261,29 @@ it('should have correct type when creating store with devtool, persist and immer
   TestComponent
 })
 
+it('should have correct type when creating store with devtools', () => {
+  const useStore = create<ITestStateProps>(
+    devtools((set) => ({
+      testKey: 'test',
+      setTestKey: (testKey: string) => {
+        set((state) => ({
+          testKey: state.testKey + testKey,
+        }))
+      },
+    }))
+  )
+
+  const TestComponent = (): JSX.Element => {
+    useStore().testKey
+    useStore().setTestKey('')
+    useStore.getState().testKey
+    useStore.getState().setTestKey('')
+
+    return <></>
+  }
+  TestComponent
+})
+
 it('should have correct type when creating store with redux', () => {
   const useStore = create(
     redux<{ count: number }, { type: 'INC' }>(
@@ -296,6 +308,31 @@ it('should have correct type when creating store with redux', () => {
   TestComponent
 })
 
+it('should combine devtools and immer', () => {
+  const useStore = create<ITestStateProps>(
+    devtools(
+      immer((set) => ({
+        testKey: 'test',
+        setTestKey: (testKey: string) => {
+          set((state) => {
+            state.testKey = testKey
+          })
+        },
+      }))
+    )
+  )
+
+  const TestComponent = (): JSX.Element => {
+    useStore().testKey
+    useStore().setTestKey('')
+    useStore.getState().testKey
+    useStore.getState().setTestKey('')
+
+    return <></>
+  }
+  TestComponent
+})
+
 it('should combine devtools and redux', () => {
   const useStore = create(
     devtools(
@@ -346,7 +383,9 @@ it('should combine subscribeWithSelector and combine', () => {
   const useStore = create(
     subscribeWithSelector(
       combine({ count: 1 }, (set, get) => ({
-        inc: () => set({ count: get().count + 1 }, false, 'inc'),
+        inc: () => set({ count: get().count + 1 }, false),
+        // FIXME hope this to fail // @ts-expect-error
+        incInvalid: () => set({ count: get().count + 1 }, false, 'inc'),
       }))
     )
   )