diff --git a/packages/core/src/Accordion/AccordionRoot.vue b/packages/core/src/Accordion/AccordionRoot.vue
index 83a141851..0c20ee5c3 100644
--- a/packages/core/src/Accordion/AccordionRoot.vue
+++ b/packages/core/src/Accordion/AccordionRoot.vue
@@ -83,7 +83,7 @@ const emits = defineEmits<AccordionRootEmits<S>>()
 defineSlots<{
   default: (props: {
     /** Current active value */
-    modelValue: typeof modelValue.value
+    modelValue: SingleOrMultipleTypeProps<S, T>['modelValue']
   }) => any
 }>()
 
@@ -113,6 +113,6 @@ provideAccordionRootContext({
     :as-child="asChild"
     :as="as"
   >
-    <slot :model-value="modelValue" />
+    <slot :model-value="modelValue as any" />
   </Primitive>
 </template>
diff --git a/packages/core/src/Combobox/ComboboxRoot.vue b/packages/core/src/Combobox/ComboboxRoot.vue
index f33757c13..c51a20aae 100644
--- a/packages/core/src/Combobox/ComboboxRoot.vue
+++ b/packages/core/src/Combobox/ComboboxRoot.vue
@@ -3,7 +3,7 @@ import type { Ref } from 'vue'
 import type { ListboxRootProps } from '@/Listbox'
 import { createContext, useDirection, useFilter } from '@/shared'
 import { usePrimitiveElement } from '@/Primitive'
-import type { AcceptableValue, GenericComponentInstance } from '@/shared/types'
+import type { AcceptableValue, GenericComponentInstance, SingleOrMultipleProps } from '@/shared/types'
 
 type ComboboxRootContext<T> = {
   modelValue: Ref<T | Array<T>>
@@ -76,7 +76,7 @@ defineSlots<{
     /** Current open state */
     open: typeof open.value
     /** Current active value */
-    modelValue: typeof modelValue.value
+    modelValue: SingleOrMultipleProps<S, T>['modelValue']
   }) => any
 }>()
 
@@ -239,7 +239,7 @@ provideComboboxRootContext({
     >
       <slot
         :open="open"
-        :model-value="modelValue"
+        :model-value="modelValue as any"
       />
     </ListboxRoot>
   </PopperRoot>
diff --git a/packages/core/src/Listbox/ListboxRoot.vue b/packages/core/src/Listbox/ListboxRoot.vue
index 5b008132c..342d7d741 100644
--- a/packages/core/src/Listbox/ListboxRoot.vue
+++ b/packages/core/src/Listbox/ListboxRoot.vue
@@ -56,7 +56,7 @@ export interface ListboxRootProps<S extends boolean = false, T = AcceptableValue
   by?: string | ((a: T, b: T) => boolean)
 }
 
-export type ListboxRootEmits<S extends boolean = false, T = AcceptableValue> = {
+export type ListboxRootEmits<S extends boolean = false, T extends AcceptableValue = AcceptableValue> = {
   /** Event handler called when the value changes. */
   'update:modelValue': [value: S extends true ? T[] : T]
   /** Event handler when highlighted element changes. */
@@ -79,12 +79,12 @@ const props = withDefaults(defineProps<ListboxRootProps<S, T>>(), {
   selectionBehavior: 'toggle',
   orientation: 'vertical',
 })
-const emits = defineEmits<ListboxRootEmits<S>>()
+const emits = defineEmits<ListboxRootEmits<S, T>>()
 
 defineSlots<{
   default: (props: {
     /** Current active value */
-    modelValue: typeof modelValue.value
+    modelValue: SingleOrMultipleProps<S, T>['modelValue']
   }) => any
 }>()
 
@@ -392,7 +392,7 @@ provideListboxRootContext({
       }
     }"
   >
-    <slot :model-value="modelValue" />
+    <slot :model-value="modelValue as any" />
 
     <VisuallyHiddenInput
       v-if="isFormControl && name"
diff --git a/packages/core/src/Select/SelectRoot.vue b/packages/core/src/Select/SelectRoot.vue
index 58ced0b0d..1d37566fc 100644
--- a/packages/core/src/Select/SelectRoot.vue
+++ b/packages/core/src/Select/SelectRoot.vue
@@ -75,7 +75,7 @@ const emits = defineEmits<SelectRootEmits<S, T>>()
 defineSlots<{
   default: (props: {
     /** Current input values */
-    modelValue: typeof modelValue.value
+    modelValue: SingleOrMultipleProps<S, T>['modelValue']
     /** Current open state */
     open: typeof open.value
   }) => any
@@ -172,7 +172,7 @@ provideSelectRootContext({
 <template>
   <PopperRoot>
     <slot
-      :model-value="modelValue"
+      :model-value="modelValue as any"
       :open="open"
     />
 
diff --git a/packages/core/src/ToggleGroup/ToggleGroupRoot.vue b/packages/core/src/ToggleGroup/ToggleGroupRoot.vue
index c0f60499c..bc9920a0f 100644
--- a/packages/core/src/ToggleGroup/ToggleGroupRoot.vue
+++ b/packages/core/src/ToggleGroup/ToggleGroupRoot.vue
@@ -5,7 +5,7 @@ import type { AcceptableValue, DataOrientation, Direction, FormFieldProps, Singl
 import { createContext, useDirection, useFormControl, useForwardExpose } from '@/shared'
 import VisuallyHiddenInput from '@/VisuallyHidden/VisuallyHiddenInput.vue'
 
-export interface ToggleGroupRootProps<S extends SingleOrMultipleType = SingleOrMultipleType, T = AcceptableValue | AcceptableValue[]>
+export interface ToggleGroupRootProps<S extends SingleOrMultipleType = SingleOrMultipleType, T extends AcceptableValue = AcceptableValue>
   extends PrimitiveProps, FormFieldProps, SingleOrMultipleTypeProps<S, T> {
   /** When `false`, navigating through the items using arrow keys will be disabled. */
   rovingFocus?: boolean
@@ -18,9 +18,9 @@ export interface ToggleGroupRootProps<S extends SingleOrMultipleType = SingleOrM
   /** When `loop` and `rovingFocus` is `true`, keyboard navigation will loop from last item to first, and vice versa. */
   loop?: boolean
 }
-export type ToggleGroupRootEmits<U extends SingleOrMultipleType = SingleOrMultipleType> = {
+export type ToggleGroupRootEmits<S extends SingleOrMultipleType = SingleOrMultipleType, T extends AcceptableValue = AcceptableValue> = {
   /** Event handler called when the value changes. */
-  'update:modelValue': [payload: (U extends 'single' ? AcceptableValue : AcceptableValue[]) ]
+  'update:modelValue': [payload: (S extends 'single' ? T : T[]) ]
 }
 
 interface ToggleGroupRootContext {
@@ -49,12 +49,12 @@ const props = withDefaults(defineProps<ToggleGroupRootProps<S, T>>(), {
   rovingFocus: true,
   disabled: false,
 })
-const emits = defineEmits<ToggleGroupRootEmits<S>>()
+const emits = defineEmits<ToggleGroupRootEmits<S, T>>()
 
 defineSlots<{
   default: (props: {
     /** Current toggle values */
-    modelValue: typeof modelValue.value
+    modelValue: SingleOrMultipleTypeProps<S, T>['modelValue']
   }) => any
 }>()
 
@@ -91,7 +91,7 @@ provideToggleGroupRootContext({
       :as-child="asChild"
       :as="as"
     >
-      <slot :model-value="modelValue" />
+      <slot :model-value="modelValue as any" />
 
       <VisuallyHiddenInput
         v-if="isFormControl && name"
diff --git a/packages/core/src/ToggleGroup/story/ToggleGroup.story.vue b/packages/core/src/ToggleGroup/story/ToggleGroup.story.vue
index 32291d10b..55242ca6b 100644
--- a/packages/core/src/ToggleGroup/story/ToggleGroup.story.vue
+++ b/packages/core/src/ToggleGroup/story/ToggleGroup.story.vue
@@ -4,7 +4,7 @@ import { ref } from 'vue'
 import { ToggleGroupItem, ToggleGroupRoot } from '..'
 
 const toggleStateSingle = ref<string | null>(null)
-const toggleStateMultiple = ref<string[] | string | null>('123')
+const toggleStateMultiple = ref<string[] | null>(['123'])
 
 const toggleGroupItemClasses
   = 'hover:bg-violet3 color-mauve11 data-[state=on]:bg-violet6 data-[state=on]:text-violet12 flex h-[35px] w-[35px] items-center justify-center bg-white text-base leading-4 first:rounded-l last:rounded-r focus:z-10 focus:shadow-[0_0_0_2px] focus:shadow-black focus:outline-none'
@@ -54,7 +54,6 @@ const toggleGroupItemClasses
       <br>
       <ToggleGroupRoot
         v-model="toggleStateMultiple"
-        type="multiple"
         class="flex"
       >
         <ToggleGroupItem
diff --git a/packages/core/src/Tree/TreeRoot.vue b/packages/core/src/Tree/TreeRoot.vue
index 7df82728f..4baacd845 100644
--- a/packages/core/src/Tree/TreeRoot.vue
+++ b/packages/core/src/Tree/TreeRoot.vue
@@ -3,7 +3,7 @@ import { createContext, useDirection, useSelectionBehavior, useTypeahead } from
 import type { Direction, SingleOrMultipleProps } from '@/shared/types'
 import { flatten } from './utils'
 
-export interface TreeRootProps<S extends boolean = false, T = Record<string, any>, U extends Record<string, any> = Record<string, any>> extends PrimitiveProps, SingleOrMultipleProps<S, U> {
+export interface TreeRootProps<S extends boolean = false, T extends Record<string, any> = Record<string, any>, U extends Record<string, any> = Record<string, any>> extends PrimitiveProps, SingleOrMultipleProps<S, U> {
   /** List of items */
   items?: T[]
   /** The controlled value of the expanded item. Can be binded with with `v-model`. */
@@ -24,8 +24,8 @@ export interface TreeRootProps<S extends boolean = false, T = Record<string, any
   propagateSelect?: boolean
 }
 
-export type TreeRootEmits<S extends boolean = false, T = Record<string, any>> = {
-  'update:modelValue': [val: S extends false ? T : T[]]
+export type TreeRootEmits<S extends boolean = false, U extends Record<string, any> = Record<string, any>> = {
+  'update:modelValue': [val: S extends false ? U : U[]]
   'update:expanded': [val: string[]]
 }
 
@@ -83,7 +83,7 @@ const emits = defineEmits<TreeRootEmits<S, U>>()
 defineSlots<{
   default: (props: {
     flattenItems: FlattenedItem<T>[]
-    modelValue: typeof modelValue.value
+    modelValue: SingleOrMultipleProps<S, U>['modelValue']
     expanded: typeof expanded.value
   }) => any
 }>()
@@ -245,7 +245,7 @@ provideTreeRootContext({
     >
       <slot
         :flatten-items="expandedItems"
-        :model-value="modelValue"
+        :model-value="modelValue as any"
         :expanded="expanded"
       />
     </Primitive>
diff --git a/packages/core/src/shared/types.ts b/packages/core/src/shared/types.ts
index 8f6d1855b..f1a246346 100644
--- a/packages/core/src/shared/types.ts
+++ b/packages/core/src/shared/types.ts
@@ -25,14 +25,14 @@ interface SingleOrMultipleTypeProps<U extends SingleOrMultipleType = SingleOrMul
    *
    * Use this when you need to control the state of the items. Can be binded with `v-model`
    */
-  modelValue?: ValueType<U, T>
+  modelValue?: ValueType<U, T> | null
 
   /**
    * The default active value of the item(s).
    *
    * Use when you do not need to control the state of the item(s).
    */
-  defaultValue?: ValueType<U, T>
+  defaultValue?: ValueType<U, T> | null
 }
 
 interface SingleOrMultipleProps<S extends boolean = boolean, T = any> {
@@ -44,14 +44,14 @@ interface SingleOrMultipleProps<S extends boolean = boolean, T = any> {
    *
    * Use this when you need to control the state of the items. Can be binded with `v-model`
    */
-  modelValue?: ValueType2<S, T>
+  modelValue?: ValueType2<S, T> | null
 
   /**
    * The default active value of the item(s).
    *
    * Use when you do not need to control the state of the item(s).
    */
-  defaultValue?: ValueType2<S, T>
+  defaultValue?: ValueType2<S, T> | null
 }
 
 /**