diff --git a/src/compiler/compile/nodes/Element.ts b/src/compiler/compile/nodes/Element.ts
index 903de939bb..bb3b26de63 100644
--- a/src/compiler/compile/nodes/Element.ts
+++ b/src/compiler/compile/nodes/Element.ts
@@ -11,7 +11,7 @@ import StyleDirective from './StyleDirective';
 import Text from './Text';
 import { namespaces } from '../../utils/namespaces';
 import map_children from './shared/map_children';
-import { regex_dimensions, regex_starts_with_newline, regex_non_whitespace_character, regex_box_size, regex_border_box_size, regex_content_box_size } from '../../utils/patterns';
+import { regex_dimensions, regex_starts_with_newline, regex_non_whitespace_character, regex_box_size } from '../../utils/patterns';
 import fuzzymatch from '../../utils/fuzzymatch';
 import list from '../../utils/list';
 import Let from './Let';
diff --git a/src/compiler/compile/render_dom/wrappers/Element/Binding.ts b/src/compiler/compile/render_dom/wrappers/Element/Binding.ts
index aa4a2d35da..103e26a210 100644
--- a/src/compiler/compile/render_dom/wrappers/Element/Binding.ts
+++ b/src/compiler/compile/render_dom/wrappers/Element/Binding.ts
@@ -416,13 +416,7 @@ function get_value_from_dom(
 
 	// <div bind:contentRect|contentBoxSize|borderBoxSize|devicePixelContentBoxSize>
 	if (regex_box_size.test(name)) {
-		const functionName = ({
-			"contentRect": "get_content_rect",
-			"contentBoxSize": "get_content_box_size",
-			"borderBoxSize": "get_border_box_size",
-			"devicePixelContentBoxSize": "get_device_pixel_content_box_size",
-		})[name];
-		return x`@${functionName}(this)`;
+		return x`@ResizeObserverSingleton.entries.get(this)?.${name}`;
 	}
 
 	// <select bind:value='selected>
diff --git a/src/compiler/compile/render_dom/wrappers/Element/index.ts b/src/compiler/compile/render_dom/wrappers/Element/index.ts
index eeb537b9db..d38fbf532d 100644
--- a/src/compiler/compile/render_dom/wrappers/Element/index.ts
+++ b/src/compiler/compile/render_dom/wrappers/Element/index.ts
@@ -70,15 +70,10 @@ const events = [
 			regex_dimensions.test(name)
 	},
 
-	{
-		event_names: ['elementresizeobservecontentrect'],
-		filter: (_node: Element, name: string) =>
-			regex_content_rect.test(name)
-	},
 	{
 		event_names: ['elementresizeobservecontentbox'],
 		filter: (_node: Element, name: string) =>
-			regex_content_box_size.test(name)
+			regex_content_rect.test(name) ?? regex_content_box_size.test(name)
 	},
 	{
 		event_names: ['elementresizeobserveborderbox'],
@@ -710,11 +705,10 @@ export default class ElementWrapper extends Wrapper {
 
 		binding_group.events.forEach(name => {
 			const resizeListenerFunctions = {
-				"elementresize": "add_iframe_resize_listener",
-				"elementresizeobservecontentrect": "add_content_rect_observer",
-				"elementresizeobservecontentbox": "add_content_box_observer",
-				"elementresizeobserveborderbox": "add_border_box_observer",
-				"elementresizeobservedevicepixelcontentbox": "add_device_pixel_content_box_observer",
+				elementresize: 'add_iframe_resize_listener',
+				elementresizeobservecontentbox: 'resize_observer_content_box.observe',
+				elementresizeobserveborderbox: 'resize_observer_border_box.observe',
+				elementresizeobservedevicepixelcontentbox: 'resize_observer_device_pixel_content_box.observe'
 			};
 
 			if (name in resizeListenerFunctions) {
diff --git a/src/compiler/utils/patterns.ts b/src/compiler/utils/patterns.ts
index e4cf3a8506..f0fb08c7c9 100644
--- a/src/compiler/utils/patterns.ts
+++ b/src/compiler/utils/patterns.ts
@@ -27,4 +27,4 @@ export const regex_content_rect = /^(?:contentRect)$/;
 export const regex_content_box_size = /^(?:contentBoxSize)$/;
 export const regex_border_box_size = /^(?:borderBoxSize)$/;
 export const regex_device_pixel_content_box_size = /^(?:devicePixelContentBoxSize)$/;
-export const regex_box_size = /^(?:contentRect|contentBoxSize|borderBoxSize|devicePixelContentBoxSize)$/
\ No newline at end of file
+export const regex_box_size = /^(?:contentRect|contentBoxSize|borderBoxSize|devicePixelContentBoxSize)$/;
diff --git a/src/runtime/internal/ResizeObserverSingleton.ts b/src/runtime/internal/ResizeObserverSingleton.ts
index 8232e4fce1..bd459a39c2 100644
--- a/src/runtime/internal/ResizeObserverSingleton.ts
+++ b/src/runtime/internal/ResizeObserverSingleton.ts
@@ -1,4 +1,4 @@
-const MapImplementation = "WeakMap" in window ? WeakMap : ("Map" in window ? Map : undefined);
+const MapImplementation = 'WeakMap' in window ? WeakMap : ('Map' in window ? Map : undefined);
 
 /**
  * Resize observer singleton
@@ -7,35 +7,27 @@ const MapImplementation = "WeakMap" in window ? WeakMap : ("Map" in window ? Map
 export class ResizeObserverSingleton {
 	constructor(readonly options?: ResizeObserverOptions) {}
 
-	addListener(element: Element, listener: Listener) {
-		this._subscriptions.set(element, {listener});
+	observe(element: Element, listener: Listener) {
+		this._listeners.set(element, listener);
 		this._getObserver().observe(element, this.options);
-		return ()=>{
-			this._subscriptions.delete(element);
-			this._observer!.unobserve(element); // this line can probably be removed
-		}
+		return () => {
+			this._listeners.delete(element);
+			this._observer.unobserve(element); // this line can probably be removed
+		};
 	}
 
-	getLastEntry(element: Element) {
-		return this._subscriptions.get(element)?.lastEntry;
-	}
+	static readonly entries: WeakMap<Element, ResizeObserverEntry> = MapImplementation ? new MapImplementation() : undefined;
 
-	private readonly _subscriptions: WeakMap<Element, Subscription> = MapImplementation ? new MapImplementation() : undefined;
+	private readonly _listeners: WeakMap<Element, Listener> = MapImplementation ? new MapImplementation() : undefined;
 	private _observer?: ResizeObserver;
 	private _getObserver() {
-		return this._observer ?? (this._observer = new ResizeObserver((entries)=>{
+		return this._observer ?? (this._observer = new ResizeObserver((entries) => {
 			for (const entry of entries) {
-				const subscription = this._subscriptions.get(entry.target)!;
-				subscription.lastEntry = entry;
-				subscription.listener(entry);
+				ResizeObserverSingleton.entries.set(entry.target, entry);
+				this._listeners.get(entry.target)?.(entry);
 			}
 		}));
 	}
 }
 
 type Listener = (entry: ResizeObserverEntry)=>any;
-
-interface Subscription {
-	readonly listener: Listener,
-	lastEntry?: ResizeObserverEntry,
-}
\ No newline at end of file
diff --git a/src/runtime/internal/dom.ts b/src/runtime/internal/dom.ts
index 26af5cb6f3..f1b2a2bb14 100644
--- a/src/runtime/internal/dom.ts
+++ b/src/runtime/internal/dom.ts
@@ -641,43 +641,11 @@ export function add_iframe_resize_listener(node: HTMLElement, fn: () => void) {
 	};
 }
 
-const resize_observer_content_rect = new ResizeObserverSingleton({ box: "content-box" });
-const resize_observer_content_box = new ResizeObserverSingleton({ box: "content-box" });
-const resize_observer_border_box = new ResizeObserverSingleton({ box: "border-box" });
-const resize_observer_device_pixel_content_box = new ResizeObserverSingleton({ box: "device-pixel-content-box" });
-
-export function add_content_rect_observer(node: Element, fn: () => void) {
-	return resize_observer_content_rect.addListener(node, fn);
-}
-
-export function add_content_box_observer(node: Element, fn: () => void) {
-	return resize_observer_content_box.addListener(node, fn);
-}
-
-export function add_border_box_observer(node: Element, fn: () => void) {
-	return resize_observer_border_box.addListener(node, fn);
-}
-
-export function add_device_pixel_content_box_observer(node: Element, fn: () => void) {
-	return resize_observer_device_pixel_content_box.addListener(node, fn);
-}
-
-export function get_content_rect(node: Element) {
-	return resize_observer_content_rect.getLastEntry(node)?.contentRect;
-}
-
-export function get_content_box_size(node: Element) {
-	return resize_observer_content_box.getLastEntry(node)?.contentBoxSize;
-}
-
-export function get_border_box_size(node: Element) {
-	return resize_observer_border_box.getLastEntry(node)?.borderBoxSize;
-}
-
-export function get_device_pixel_content_box_size(node: Element) {
-	return resize_observer_device_pixel_content_box.getLastEntry(node)?.devicePixelContentBoxSize;
-}
-
+export const resize_observer_content_rect = new ResizeObserverSingleton({ box: 'content-box' });
+export const resize_observer_content_box = new ResizeObserverSingleton({ box: 'content-box' });
+export const resize_observer_border_box = new ResizeObserverSingleton({ box: 'border-box' });
+export const resize_observer_device_pixel_content_box = new ResizeObserverSingleton({ box: 'device-pixel-content-box' });
+export { ResizeObserverSingleton };
 
 export function toggle_class(element, name, toggle) {
 	element.classList[toggle ? 'add' : 'remove'](name);