diff --git a/packages/demo/src/material-ui/material-ui-custom.tsx b/packages/demo/src/material-ui/material-ui-custom.tsx
index 8c563028..5022f533 100644
--- a/packages/demo/src/material-ui/material-ui-custom.tsx
+++ b/packages/demo/src/material-ui/material-ui-custom.tsx
@@ -11,7 +11,7 @@ import {
     StoreKeys, StoreSchemaType, WidgetProps,
     UIMetaProvider, UIStoreProvider, useUIMeta,
     WithValue, extractValue,
-    WidgetsBindingFactory, WithScalarValue,
+    WidgetsBindingFactory, WithScalarValue, onChangeHandler,
 } from '@ui-schema/ui-schema'
 import { browserT } from '../t'
 import { UIApiProvider, loadSchemaUIApi } from '@ui-schema/ui-schema/UIApi'
@@ -194,7 +194,7 @@ const FreeFormEditor = () => {
     const showValidity = true
     const [store, setStore] = React.useState(() => createStore(OrderedMap()))
 
-    const onChange = React.useCallback((actions) => {
+    const onChange: onChangeHandler = React.useCallback((actions) => {
         setStore(storeUpdater(actions))
     }, [setStore])
 
diff --git a/packages/ui-schema/src/UIStore/UIStoreProvider.tsx b/packages/ui-schema/src/UIStore/UIStoreProvider.tsx
index efd6869f..e6f73b25 100644
--- a/packages/ui-schema/src/UIStore/UIStoreProvider.tsx
+++ b/packages/ui-schema/src/UIStore/UIStoreProvider.tsx
@@ -63,19 +63,19 @@ export interface WithOnChange<A = UIStoreActions> {
 export interface WithValue<A = UIStoreActions> {
     value: any | undefined
     internalValue: any | undefined
-    showValidity: UIStoreContext['showValidity']
+    showValidity?: UIStoreContext['showValidity']
     onChange: onChangeHandler<A>
 }
 
 export interface WithScalarValue<A = UIStoreActions> {
     value: string | number | boolean | undefined | null
     internalValue: any
-    showValidity: UIStoreContext['showValidity']
+    showValidity?: UIStoreContext['showValidity']
     onChange: onChangeHandler<A>
 }
 
 export interface WithValidity<A = UIStoreActions> {
     validity: any
     onChange: onChangeHandler<A>
-    showValidity: UIStoreContext['showValidity']
+    showValidity?: UIStoreContext['showValidity']
 }
diff --git a/packages/ui-schema/src/UIStoreActions/UIStoreActions.ts b/packages/ui-schema/src/UIStoreActions/UIStoreActions.ts
index 80a07d7f..31580239 100644
--- a/packages/ui-schema/src/UIStoreActions/UIStoreActions.ts
+++ b/packages/ui-schema/src/UIStoreActions/UIStoreActions.ts
@@ -13,49 +13,52 @@ export type UIStoreActionScoped<S extends UIStoreType = UIStoreType, D extends U
     effect?: (newData: D, newStore: S) => void
 }
 
-export interface UIStoreAction extends UIStoreActionScoped {
+export interface UIStoreAction<S extends UIStoreType = UIStoreType, D extends UIStoreUpdaterData = UIStoreUpdaterData> extends UIStoreActionScoped<S, D> {
     type: string
     schema?: StoreSchemaType
     required?: boolean
 }
 
-export type UIStoreActionListItemAdd = UIStoreActionListItemAddWithValue | UIStoreActionListItemAddWithSchema
 
-export interface UIStoreActionListItemAddWithValue extends UIStoreAction {
+export interface UIStoreActionListItemAddWithValue<S extends UIStoreType = UIStoreType, D extends UIStoreUpdaterData = UIStoreUpdaterData> extends UIStoreAction<S, D> {
     type: 'list-item-add'
     itemValue: any
 }
 
-export interface UIStoreActionListItemAddWithSchema extends UIStoreAction {
+export interface UIStoreActionListItemAddWithSchema<S extends UIStoreType = UIStoreType, D extends UIStoreUpdaterData = UIStoreUpdaterData> extends UIStoreAction<S, D> {
     type: 'list-item-add'
     schema: StoreSchemaType
 }
 
-export interface UIStoreActionListItemDelete extends UIStoreAction {
+export type UIStoreActionListItemAdd<S extends UIStoreType = UIStoreType, D extends UIStoreUpdaterData = UIStoreUpdaterData> =
+    UIStoreActionListItemAddWithValue<S, D> |
+    UIStoreActionListItemAddWithSchema<S, D>
+
+export interface UIStoreActionListItemDelete<S extends UIStoreType = UIStoreType, D extends UIStoreUpdaterData = UIStoreUpdaterData> extends UIStoreAction<S, D> {
     type: 'list-item-delete'
     index: number
 }
 
-export interface UIStoreActionListItemMove extends UIStoreAction {
+export interface UIStoreActionListItemMove<S extends UIStoreType = UIStoreType, D extends UIStoreUpdaterData = UIStoreUpdaterData> extends UIStoreAction<S, D> {
     type: 'list-item-move'
     fromIndex: number
     toIndex: number
 }
 
-export interface UIStoreActionUpdate<D extends UIStoreUpdaterData = UIStoreUpdaterData> extends UIStoreAction {
+export interface UIStoreActionUpdate<S extends UIStoreType = UIStoreType, D extends UIStoreUpdaterData = UIStoreUpdaterData> extends UIStoreAction<S, D> {
     type: 'update'
     updater: UIStoreUpdaterFn<D>
 }
 
-export interface UIStoreActionSet<D extends UIStoreUpdaterData = UIStoreUpdaterData> extends UIStoreAction {
+export interface UIStoreActionSet<S extends UIStoreType = UIStoreType, D extends UIStoreUpdaterData = UIStoreUpdaterData> extends UIStoreAction<S, D> {
     type: 'set'
     data: D
 }
 
-export type UIStoreActions<D extends UIStoreUpdaterData = UIStoreUpdaterData> =
-    UIStoreActionListItemAdd |
-    UIStoreActionListItemDelete |
-    UIStoreActionListItemMove |
-    UIStoreActionUpdate<D> |
-    UIStoreActionSet<D>
+export type UIStoreActions<S extends UIStoreType = UIStoreType, D extends UIStoreUpdaterData = UIStoreUpdaterData> =
+    UIStoreActionListItemAdd<S, D> |
+    UIStoreActionListItemDelete<S, D> |
+    UIStoreActionListItemMove<S, D> |
+    UIStoreActionUpdate<S, D> |
+    UIStoreActionSet<S, D>
 
diff --git a/packages/ui-schema/src/storeUpdater/storeActionHandler.ts b/packages/ui-schema/src/storeUpdater/storeActionHandler.ts
index 20eba9b3..071eaca7 100644
--- a/packages/ui-schema/src/storeUpdater/storeActionHandler.ts
+++ b/packages/ui-schema/src/storeUpdater/storeActionHandler.ts
@@ -1,8 +1,8 @@
-import { UIStoreUpdaterFn } from '@ui-schema/ui-schema/UIStore'
+import { UIStoreType, UIStoreUpdaterFn } from '@ui-schema/ui-schema/UIStore'
 import { UIStoreActions, UIStoreUpdaterData } from '@ui-schema/ui-schema/UIStoreActions'
 import { storeActionReducers } from '@ui-schema/ui-schema/storeUpdater/storeActionReducers'
 
 /**
  * @deprecated use `storeActionReducers` instead
  */
-export const storeActionHandler = storeActionReducers as <D extends UIStoreUpdaterData = UIStoreUpdaterData, A extends UIStoreActions<D> = UIStoreActions<D>>(action: A) => UIStoreUpdaterFn<D> | D
+export const storeActionHandler = storeActionReducers as <S extends UIStoreType = UIStoreType, D extends UIStoreUpdaterData = UIStoreUpdaterData, A = UIStoreActions<S, D>>(action: A) => UIStoreUpdaterFn<D> | D
diff --git a/packages/ui-schema/src/storeUpdater/storeActionReducers.ts b/packages/ui-schema/src/storeUpdater/storeActionReducers.ts
index da391eea..3df47afd 100644
--- a/packages/ui-schema/src/storeUpdater/storeActionReducers.ts
+++ b/packages/ui-schema/src/storeUpdater/storeActionReducers.ts
@@ -1,10 +1,12 @@
-import { UIStoreUpdaterFn } from '@ui-schema/ui-schema/UIStore'
+import { UIStoreType, UIStoreUpdaterFn } from '@ui-schema/ui-schema/UIStore'
 import { List, Map, OrderedMap } from 'immutable'
 import { moveItem } from '@ui-schema/ui-schema/Utils/moveItem'
 import { SchemaTypesType } from '@ui-schema/ui-schema/CommonTypings'
 import { UIStoreActions, UIStoreUpdaterData } from '@ui-schema/ui-schema/UIStoreActions'
 
-export const storeActionReducers = <D extends UIStoreUpdaterData = UIStoreUpdaterData, A extends UIStoreActions<D> = UIStoreActions<D>>(action: A): UIStoreUpdaterFn<D> | D => {
+export const storeActionReducers = <S extends UIStoreType = UIStoreType, D extends UIStoreUpdaterData = UIStoreUpdaterData, A extends UIStoreActions<S, D> = UIStoreActions<S, D>>(
+    action: A
+): UIStoreUpdaterFn<D> | D => {
     switch (action.type) {
         case 'list-item-add':
             return ({value = List(), internal = Map(), ...r}) => {
diff --git a/packages/ui-schema/src/storeUpdater/storeUpdater.ts b/packages/ui-schema/src/storeUpdater/storeUpdater.ts
index e476f397..38d40322 100644
--- a/packages/ui-schema/src/storeUpdater/storeUpdater.ts
+++ b/packages/ui-schema/src/storeUpdater/storeUpdater.ts
@@ -4,18 +4,18 @@ import {
     UIStoreStateData, UIStoreUpdaterFn,
 } from '@ui-schema/ui-schema/UIStore'
 import { scopeUpdaterValues, scopeUpdaterInternals, scopeUpdaterValidity } from '@ui-schema/ui-schema/storeScopeUpdater'
-import { UIStoreActions, UIStoreUpdaterData } from '@ui-schema/ui-schema/UIStoreActions'
+import { UIStoreAction, UIStoreActions, UIStoreUpdaterData } from '@ui-schema/ui-schema/UIStoreActions'
 import { storeActionReducers } from '@ui-schema/ui-schema/storeUpdater'
 
 // todo: unify this type and the `setter` in `ScopeUpdaterMapType`
-export type ScopeOnChangeHandler<S extends UIStoreType = UIStoreType, A extends UIStoreActions = UIStoreActions> = (
+export type ScopeOnChangeHandler<S extends UIStoreType = UIStoreType, D extends UIStoreUpdaterData = UIStoreUpdaterData, A = UIStoreActions<S, D>> = (
     store: S,
     storeKeys: StoreKeys,
     newValue: any,
     action?: A | undefined
 ) => S
 
-export type ScopeUpdaterMapType<D extends UIStoreUpdaterData = UIStoreUpdaterData, A extends UIStoreActions = UIStoreActions> = {
+export type ScopeUpdaterMapType<S extends UIStoreType = UIStoreType, D extends UIStoreUpdaterData = UIStoreUpdaterData, A = UIStoreActions<S, D>> = {
     [k in keyof D]: ({
         setter: <S extends UIStoreType>(
             store: S,
@@ -68,7 +68,7 @@ export const scopeUpdaterMapDefault: ScopeUpdaterMapType = {
     },
 }
 
-export const createStoreUpdater = <S extends UIStoreType = UIStoreType, A extends UIStoreActions = UIStoreActions, D extends UIStoreUpdaterData = UIStoreUpdaterData, SM extends ScopeUpdaterMapType<D, A> = ScopeUpdaterMapType<D, A>>(
+export const createStoreUpdater = <S extends UIStoreType = UIStoreType, D extends UIStoreUpdaterData = UIStoreUpdaterData, A extends UIStoreAction<S, D> = UIStoreActions<S, D>, SM extends ScopeUpdaterMapType<S, D, A> = ScopeUpdaterMapType<S, D, A>>(
     actionReducers: (action: A) => UIStoreUpdaterFn<D> | D,
     scopeUpdaterMap: SM,
 ) => {
@@ -129,8 +129,11 @@ export const createStoreUpdater = <S extends UIStoreType = UIStoreType, A extend
 }
 
 export const storeUpdater =
-    <S extends UIStoreType = UIStoreType, A extends UIStoreActions = UIStoreActions>(
+    <S extends UIStoreType = UIStoreType, D extends UIStoreUpdaterData = UIStoreUpdaterData, A extends UIStoreActions<S, D> = UIStoreActions<S, D>>(
         actions: A[] | A
     ) => {
-        return createStoreUpdater<S, A>(storeActionReducers, scopeUpdaterMapDefault)(actions)
+        return createStoreUpdater<S, D, A>(
+            storeActionReducers as (action: A) => UIStoreUpdaterFn<D> | D,
+            scopeUpdaterMapDefault as ScopeUpdaterMapType<S, D, A>,
+        )(actions)
     }