diff --git a/packages/actify/src/components/ListBox/listbox.module.css b/packages/actify/src/components/ListBox/listbox.module.css
index b0034ae..360db0c 100644
--- a/packages/actify/src/components/ListBox/listbox.module.css
+++ b/packages/actify/src/components/ListBox/listbox.module.css
@@ -1,4 +1,7 @@
 .items {
+  list-style: none;
+  margin: 0;
+  padding: 0;
   display: block;
   padding-block: 8px;
   list-style-type: none;
@@ -9,6 +12,7 @@
     --md-menu-container-color,
     var(--md-sys-color-surface-container, #f3edf7)
   );
+  width: var(--reference-width);
   height: inherit;
   max-height: inherit;
   overflow: auto;
diff --git a/packages/actify/src/components/Popover/Popover.tsx b/packages/actify/src/components/Popover/Popover.tsx
index a71cda8..4127405 100644
--- a/packages/actify/src/components/Popover/Popover.tsx
+++ b/packages/actify/src/components/Popover/Popover.tsx
@@ -11,11 +11,18 @@ import type { OverlayTriggerState } from 'react-stately'
 import React from 'react'
 
 interface PopoverProps extends Omit<AriaPopoverProps, 'popoverRef'> {
+  referenceWidth?: number
   children: React.ReactNode
   state: OverlayTriggerState
 }
 
-const Popover = ({ children, state, offset = 8, ...props }: PopoverProps) => {
+const Popover = ({
+  children,
+  state,
+  offset = 8,
+  referenceWidth,
+  ...props
+}: PopoverProps) => {
   const popoverRef = React.useRef(null)
   const { popoverProps, underlayProps, arrowProps, placement } = usePopover(
     {
@@ -26,6 +33,11 @@ const Popover = ({ children, state, offset = 8, ...props }: PopoverProps) => {
     state
   )
 
+  popoverProps.style = {
+    ...popoverProps.style,
+    '--reference-width': referenceWidth + 'px'
+  } as React.CSSProperties
+
   return (
     <Overlay>
       <div {...underlayProps} className={styles['underlay']} />
diff --git a/packages/actify/src/components/Select/Select.tsx b/packages/actify/src/components/Select/Select.tsx
index 5fe53c5..5014998 100644
--- a/packages/actify/src/components/Select/Select.tsx
+++ b/packages/actify/src/components/Select/Select.tsx
@@ -21,7 +21,10 @@ interface SelectProps<T> extends AriaSelectOptions<T>, SelectStateOptions<T> {
 
 const Select = <T extends object>(props: SelectProps<T>) => {
   const state = useSelectState(props)
-  const ref = React.useRef(null)
+  const [referenceWidth, setReferenceWidth] = React.useState<
+    number | undefined
+  >(0)
+  const ref = React.useRef<HTMLButtonElement>(null)
 
   const { triggerProps, valueProps, menuProps } = useSelect(props, state, ref)
 
@@ -35,6 +38,22 @@ const Select = <T extends object>(props: SelectProps<T>) => {
     Tag = OutlinedField
   }
 
+  React.useLayoutEffect(() => {
+    const width = ref?.current?.getBoundingClientRect().width
+    setReferenceWidth(width)
+  }, [])
+
+  React.useEffect(() => {
+    const updateWidth = () => {
+      const width = ref?.current?.getBoundingClientRect().width
+      setReferenceWidth(width)
+    }
+    window.addEventListener('resize', updateWidth)
+    return () => {
+      window.removeEventListener('resize', updateWidth)
+    }
+  }, [])
+
   return (
     <div
       style={props.style}
@@ -56,7 +75,12 @@ const Select = <T extends object>(props: SelectProps<T>) => {
       </Tag>
 
       {state.isOpen && (
-        <Popover state={state} triggerRef={ref} placement="bottom start">
+        <Popover
+          state={state}
+          triggerRef={ref}
+          placement="bottom start"
+          referenceWidth={referenceWidth}
+        >
           <ListBox {...menuProps} state={state} />
         </Popover>
       )}