diff --git a/dev/Dev.vue b/dev/Dev.vue
index df64178..85b1762 100644
--- a/dev/Dev.vue
+++ b/dev/Dev.vue
@@ -1,22 +1,26 @@
 <template>
-  <div id="app">
+  <div class="flex items-center justify-center pt-40">
     <ListBox
       v-model="selected"
-      :open="open"
-      class="px-2 text-left border border-gray-500 rounded w-64 relative bg-blue-100 h-12"
+      v-model:open="open"
+      class="px-2 text-left border border-gray-500 rounded w-64 relative h-12"
     >
       {{ selected?.label }}
 
       <ListBoxMenu
-        class="absolute inset-0 top-12 w-full h-64 overflow-y-scroll bg-red-100 space-y-1"
+        class="absolute inset-0 top-12 w-full h-64 overflow-y-scroll space-y-1 border rounded"
       >
         <ListBoxOption
           @click="selected = country"
           v-for="country in config.options"
           :key="country.id"
-          class="px-2 py-1"
+          :class="['px-2 py-1']"
+          :value="country"
+          #default="{ isSelected }"
         >
-          {{ country.label }}
+          <span :class="{ 'text-indigo-600': isSelected }">
+            {{ country.label }}
+          </span>
         </ListBoxOption>
       </ListBoxMenu>
     </ListBox>
@@ -33,6 +37,7 @@ export default {
   components: { ListBoxOption, ListBoxMenu, ListBox },
   data: () => ({
     selected: null,
+    open: false,
 
     config: {
       options: countries,
@@ -40,26 +45,3 @@ export default {
   }),
 }
 </script>
-
-<style>
-html,
-body {
-  margin: 0;
-  height: 100%;
-  font-family: -apple-system, sans-serif;
-}
-
-#app {
-  height: 100%;
-  max-width: 20rem;
-  margin: 10rem auto 0;
-}
-
-hr {
-  border: none;
-  border-bottom: 1px solid #cacaca;
-  margin-bottom: 1em;
-  padding-top: 1em;
-  width: 90%;
-}
-</style>
diff --git a/docs/guide/opening.md b/docs/guide/opening.md
index 40613ab..dd38319 100644
--- a/docs/guide/opening.md
+++ b/docs/guide/opening.md
@@ -3,12 +3,9 @@
 By default, the dropdown will open anytime the underlying search input has focus. The dropdown will
 open when clicked, or when it has received focus when tabbing through inputs.
 
-## Customizing Dropdown Behaviour <Badge text="v3.12.0+" />
+## Customizing Dropdown Behaviour <Badge text="v4+" />
 
-The `dropdownShouldOpen` prop allows for full customization of the open/close behaviour. The prop
-accepts a `function` that should return a `boolean` value. The returned boolean value will be used
-to determine if the dropdown should be `open`/`true` or `false`/`closed`. The function receives the
-instance of the component as the only argument.
+The `open` prop can control showing and hiding the dropdown menu from a parent component. If this prop is set, the component will always use the value of `props.open` to handle showing and hiding the dropdown. Vue Select will emit the `update:open` when the prop value should change, so you can use `<VueSelect v-model:open="open" />` to have control over the `open` state while preserving default behaviour.
 
 #### Example: Open the dropdown when search text is present
 --- 
diff --git a/src/components/ListBox/ListBox.vue b/src/components/ListBox/ListBox.vue
index b5d9cac..b7bba06 100644
--- a/src/components/ListBox/ListBox.vue
+++ b/src/components/ListBox/ListBox.vue
@@ -1,25 +1,45 @@
 <script setup lang="ts">
-import { ListBoxInjectionKey } from '@/keys.js'
+import { ListBoxInjectionKey } from '@/keys'
 import type { ComputedRef, PropType } from 'vue'
-import { provide, defineEmits, computed, ref } from 'vue'
+import { provide, defineEmits, computed, reactive, watch } from 'vue'
 
 export interface ListBoxProps {
   modelValue: PropType<unknown>
-  open?: boolean
+  open?: boolean | undefined
 }
+export interface ResolvedListBoxProps extends Omit<ListBoxProps, 'open'> {
+  open: boolean
+}
+export type InjectedListBoxProps = ComputedRef<ResolvedListBoxProps>
 
-const emit = defineEmits(['update:modelValue'])
+const emit = defineEmits(['update:modelValue', 'update:open', 'open', 'close'])
 
 const props = withDefaults(defineProps<ListBoxProps>(), {
-  open: false,
+  open: undefined,
 })
 
-export type ComputedListBoxInjectionProps = ComputedRef<ListBoxProps>
+const mutableState = reactive<{
+  open: boolean
+}>({
+  open: props.open === undefined ? false : props.open,
+})
 
-provide<ComputedListBoxInjectionProps>(
+watch(
+  () => mutableState.open,
+  (open) => emit('update:open', open)
+)
+
+const isOpen = computed<boolean>(() => {
+  if (props.open !== undefined) {
+    return props.open
+  }
+  return mutableState.open
+})
+
+provide<InjectedListBoxProps>(
   ListBoxInjectionKey,
-  computed<ListBoxProps>(() => ({
-    open: props.open,
+  computed<ResolvedListBoxProps>(() => ({
+    open: isOpen.value,
     modelValue: props.modelValue,
   }))
 )
@@ -31,7 +51,7 @@ provide<ComputedListBoxInjectionProps>(
     type="button"
     aria-haspopup="true"
     :aria-expanded="open"
-    @click.exact="open = !open"
+    @click.exact="mutableState.open = !mutableState.open"
   >
     <slot></slot>
   </button>
diff --git a/src/components/ListBox/ListBoxMenu.vue b/src/components/ListBox/ListBoxMenu.vue
index 9bd6132..62b893c 100644
--- a/src/components/ListBox/ListBoxMenu.vue
+++ b/src/components/ListBox/ListBoxMenu.vue
@@ -1,7 +1,7 @@
 <script setup lang="ts">
 import { defineProps, inject } from 'vue'
 import { ListBoxInjectionKey } from '@/keys'
-import type { ComputedListBoxInjectionProps } from '@/components/ListBox/ListBox.vue'
+import type { InjectedListBoxProps } from '@/components/ListBox/ListBox.vue'
 
 withDefaults(
   defineProps<{
@@ -12,11 +12,11 @@ withDefaults(
   }
 )
 
-const listBoxProps = inject<ComputedListBoxInjectionProps>(ListBoxInjectionKey)
+const listBoxProps = inject<InjectedListBoxProps>(ListBoxInjectionKey)
 </script>
 
 <template>
-  <Component :is="as" v-show="listBoxProps?.open">
+  <Component :is="as" v-show="listBoxProps.open">
     <slot></slot>
   </Component>
 </template>
diff --git a/src/components/ListBox/ListBoxOption.vue b/src/components/ListBox/ListBoxOption.vue
index 0fb17e7..6292da3 100644
--- a/src/components/ListBox/ListBoxOption.vue
+++ b/src/components/ListBox/ListBoxOption.vue
@@ -1,18 +1,27 @@
 <script setup lang="ts">
-import { defineProps } from 'vue'
+import { computed, defineProps, inject } from 'vue'
+import type { InjectedListBoxProps } from '@/components/ListBox/ListBox.vue'
+import { ListBoxInjectionKey } from '@/keys'
 
-withDefaults(
+const props = withDefaults(
   defineProps<{
     as?: string
+    value: unknown
   }>(),
   {
     as: 'div',
   }
 )
+
+const listBoxProps = inject<InjectedListBoxProps>(ListBoxInjectionKey)
+
+const isSelected = computed(() => {
+  return listBoxProps?.value.modelValue === props.value
+})
 </script>
 
 <template>
   <Component :is="as">
-    <slot></slot>
+    <slot v-bind="{ isSelected }"></slot>
   </Component>
 </template>
diff --git a/src/keys.js b/src/keys.ts
similarity index 100%
rename from src/keys.js
rename to src/keys.ts