diff --git a/.changeset/stupid-dodos-hide.md b/.changeset/stupid-dodos-hide.md
new file mode 100644
index 0000000000..1fb49adbf1
--- /dev/null
+++ b/.changeset/stupid-dodos-hide.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+feat: unwrap function expressions where possible, and optimise bindings
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/BindDirective.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/BindDirective.js
index b7819b874c..860154e3ed 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/BindDirective.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/BindDirective.js
@@ -36,13 +36,20 @@ export function BindDirective(node, context) {
 		);
 	}
 
-	const getter = b.thunk(/** @type {Expression} */ (context.visit(expression)));
-
-	const setter = b.arrow(
-		[b.id('$$value')],
-		/** @type {Expression} */ (context.visit(b.assignment('=', expression, b.id('$$value'))))
+	const get = b.thunk(/** @type {Expression} */ (context.visit(expression)));
+
+	/** @type {Expression | undefined} */
+	let set = b.unthunk(
+		b.arrow(
+			[b.id('$$value')],
+			/** @type {Expression} */ (context.visit(b.assignment('=', expression, b.id('$$value'))))
+		)
 	);
 
+	if (get === set) {
+		set = undefined;
+	}
+
 	/** @type {CallExpression} */
 	let call;
 
@@ -52,15 +59,15 @@ export function BindDirective(node, context) {
 			b.literal(node.name),
 			b.literal(property.event),
 			context.state.node,
-			setter,
-			property.bidirectional && getter
+			set ?? get,
+			property.bidirectional && get
 		);
 	} else {
 		// special cases
 		switch (node.name) {
 			// window
 			case 'online':
-				call = b.call(`$.bind_online`, setter);
+				call = b.call(`$.bind_online`, set ?? get);
 				break;
 
 			case 'scrollX':
@@ -68,8 +75,8 @@ export function BindDirective(node, context) {
 				call = b.call(
 					'$.bind_window_scroll',
 					b.literal(node.name === 'scrollX' ? 'x' : 'y'),
-					getter,
-					setter
+					get,
+					set
 				);
 				break;
 
@@ -77,47 +84,47 @@ export function BindDirective(node, context) {
 			case 'innerHeight':
 			case 'outerWidth':
 			case 'outerHeight':
-				call = b.call('$.bind_window_size', b.literal(node.name), setter);
+				call = b.call('$.bind_window_size', b.literal(node.name), set ?? get);
 				break;
 
 			// document
 			case 'activeElement':
-				call = b.call('$.bind_active_element', setter);
+				call = b.call('$.bind_active_element', set ?? get);
 				break;
 
 			// media
 			case 'muted':
-				call = b.call(`$.bind_muted`, context.state.node, getter, setter);
+				call = b.call(`$.bind_muted`, context.state.node, get, set);
 				break;
 			case 'paused':
-				call = b.call(`$.bind_paused`, context.state.node, getter, setter);
+				call = b.call(`$.bind_paused`, context.state.node, get, set);
 				break;
 			case 'volume':
-				call = b.call(`$.bind_volume`, context.state.node, getter, setter);
+				call = b.call(`$.bind_volume`, context.state.node, get, set);
 				break;
 			case 'playbackRate':
-				call = b.call(`$.bind_playback_rate`, context.state.node, getter, setter);
+				call = b.call(`$.bind_playback_rate`, context.state.node, get, set);
 				break;
 			case 'currentTime':
-				call = b.call(`$.bind_current_time`, context.state.node, getter, setter);
+				call = b.call(`$.bind_current_time`, context.state.node, get, set);
 				break;
 			case 'buffered':
-				call = b.call(`$.bind_buffered`, context.state.node, setter);
+				call = b.call(`$.bind_buffered`, context.state.node, set ?? get);
 				break;
 			case 'played':
-				call = b.call(`$.bind_played`, context.state.node, setter);
+				call = b.call(`$.bind_played`, context.state.node, set ?? get);
 				break;
 			case 'seekable':
-				call = b.call(`$.bind_seekable`, context.state.node, setter);
+				call = b.call(`$.bind_seekable`, context.state.node, set ?? get);
 				break;
 			case 'seeking':
-				call = b.call(`$.bind_seeking`, context.state.node, setter);
+				call = b.call(`$.bind_seeking`, context.state.node, set ?? get);
 				break;
 			case 'ended':
-				call = b.call(`$.bind_ended`, context.state.node, setter);
+				call = b.call(`$.bind_ended`, context.state.node, set ?? get);
 				break;
 			case 'readyState':
-				call = b.call(`$.bind_ready_state`, context.state.node, setter);
+				call = b.call(`$.bind_ready_state`, context.state.node, set ?? get);
 				break;
 
 			// dimensions
@@ -125,28 +132,33 @@ export function BindDirective(node, context) {
 			case 'contentBoxSize':
 			case 'borderBoxSize':
 			case 'devicePixelContentBoxSize':
-				call = b.call('$.bind_resize_observer', context.state.node, b.literal(node.name), setter);
+				call = b.call(
+					'$.bind_resize_observer',
+					context.state.node,
+					b.literal(node.name),
+					set ?? get
+				);
 				break;
 
 			case 'clientWidth':
 			case 'clientHeight':
 			case 'offsetWidth':
 			case 'offsetHeight':
-				call = b.call('$.bind_element_size', context.state.node, b.literal(node.name), setter);
+				call = b.call('$.bind_element_size', context.state.node, b.literal(node.name), set ?? get);
 				break;
 
 			// various
 			case 'value': {
 				if (parent?.type === 'RegularElement' && parent.name === 'select') {
-					call = b.call(`$.bind_select_value`, context.state.node, getter, setter);
+					call = b.call(`$.bind_select_value`, context.state.node, get, set);
 				} else {
-					call = b.call(`$.bind_value`, context.state.node, getter, setter);
+					call = b.call(`$.bind_value`, context.state.node, get, set);
 				}
 				break;
 			}
 
 			case 'files':
-				call = b.call(`$.bind_files`, context.state.node, getter, setter);
+				call = b.call(`$.bind_files`, context.state.node, get, set);
 				break;
 
 			case 'this':
@@ -160,18 +172,18 @@ export function BindDirective(node, context) {
 					'$.bind_content_editable',
 					b.literal(node.name),
 					context.state.node,
-					getter,
-					setter
+					get,
+					set
 				);
 				break;
 
 			// checkbox/radio
 			case 'checked':
-				call = b.call(`$.bind_checked`, context.state.node, getter, setter);
+				call = b.call(`$.bind_checked`, context.state.node, get, set);
 				break;
 
 			case 'focused':
-				call = b.call(`$.bind_focused`, context.state.node, setter);
+				call = b.call(`$.bind_focused`, context.state.node, set ?? get);
 				break;
 
 			case 'group': {
@@ -184,7 +196,7 @@ export function BindDirective(node, context) {
 
 				// We need to additionally invoke the value attribute signal to register it as a dependency,
 				// so that when the value is updated, the group binding is updated
-				let group_getter = getter;
+				let group_getter = get;
 
 				if (parent?.type === 'RegularElement') {
 					const value = /** @type {any[]} */ (
@@ -215,7 +227,7 @@ export function BindDirective(node, context) {
 					b.array(indexes),
 					context.state.node,
 					group_getter,
-					setter
+					set ?? get
 				);
 				break;
 			}
diff --git a/packages/svelte/src/compiler/utils/builders.js b/packages/svelte/src/compiler/utils/builders.js
index 060a8c2990..fc1cdf4adb 100644
--- a/packages/svelte/src/compiler/utils/builders.js
+++ b/packages/svelte/src/compiler/utils/builders.js
@@ -419,19 +419,31 @@ export function template(elements, expressions) {
  * @returns {ESTree.Expression}
  */
 export function thunk(expression, async = false) {
+	const fn = arrow([], expression);
+	if (async) fn.async = true;
+	return unthunk(fn);
+}
+
+/**
+ * Replace "(arg) => func(arg)" to "func"
+ * @param {ESTree.Expression} expression
+ * @returns {ESTree.Expression}
+ */
+export function unthunk(expression) {
 	if (
-		expression.type === 'CallExpression' &&
-		expression.callee.type !== 'Super' &&
-		expression.callee.type !== 'MemberExpression' &&
-		expression.callee.type !== 'CallExpression' &&
-		expression.arguments.length === 0
+		expression.type === 'ArrowFunctionExpression' &&
+		expression.async === false &&
+		expression.body.type === 'CallExpression' &&
+		expression.body.callee.type === 'Identifier' &&
+		expression.params.length === expression.body.arguments.length &&
+		expression.params.every((param, index) => {
+			const arg = /** @type {ESTree.SimpleCallExpression} */ (expression.body).arguments[index];
+			return param.type === 'Identifier' && arg.type === 'Identifier' && param.name === arg.name;
+		})
 	) {
-		return expression.callee;
+		return expression.body.callee;
 	}
-
-	const fn = arrow([], expression);
-	if (async) fn.async = true;
-	return fn;
+	return expression;
 }
 
 /**
diff --git a/packages/svelte/src/internal/client/dom/elements/bindings/input.js b/packages/svelte/src/internal/client/dom/elements/bindings/input.js
index 35dd229d39..a1406925f5 100644
--- a/packages/svelte/src/internal/client/dom/elements/bindings/input.js
+++ b/packages/svelte/src/internal/client/dom/elements/bindings/input.js
@@ -8,18 +8,18 @@ import { hydrating } from '../../hydration.js';
 
 /**
  * @param {HTMLInputElement} input
- * @param {() => unknown} get_value
- * @param {(value: unknown) => void} update
+ * @param {() => unknown} get
+ * @param {(value: unknown) => void} set
  * @returns {void}
  */
-export function bind_value(input, get_value, update) {
+export function bind_value(input, get, set = get) {
 	listen_to_event_and_reset_event(input, 'input', () => {
 		if (DEV && input.type === 'checkbox') {
 			// TODO should this happen in prod too?
 			e.bind_invalid_checkbox_value();
 		}
 
-		update(is_numberlike_input(input) ? to_number(input.value) : input.value);
+		set(is_numberlike_input(input) ? to_number(input.value) : input.value);
 	});
 
 	render_effect(() => {
@@ -28,12 +28,12 @@ export function bind_value(input, get_value, update) {
 			e.bind_invalid_checkbox_value();
 		}
 
-		var value = get_value();
+		var value = get();
 
 		// If we are hydrating and the value has since changed, then use the update value
 		// from the input instead.
 		if (hydrating && input.defaultValue !== input.value) {
-			update(input.value);
+			set(input.value);
 			return;
 		}
 
@@ -60,11 +60,11 @@ const pending = new Set();
  * @param {HTMLInputElement[]} inputs
  * @param {null | [number]} group_index
  * @param {HTMLInputElement} input
- * @param {() => unknown} get_value
- * @param {(value: unknown) => void} update
+ * @param {() => unknown} get
+ * @param {(value: unknown) => void} set
  * @returns {void}
  */
-export function bind_group(inputs, group_index, input, get_value, update) {
+export function bind_group(inputs, group_index, input, get, set = get) {
 	var is_checkbox = input.getAttribute('type') === 'checkbox';
 	var binding_group = inputs;
 
@@ -91,14 +91,14 @@ export function bind_group(inputs, group_index, input, get_value, update) {
 				value = get_binding_group_value(binding_group, value, input.checked);
 			}
 
-			update(value);
+			set(value);
 		},
 		// TODO better default value handling
-		() => update(is_checkbox ? [] : null)
+		() => set(is_checkbox ? [] : null)
 	);
 
 	render_effect(() => {
-		var value = get_value();
+		var value = get();
 
 		// If we are hydrating and the value has since changed, then use the update value
 		// from the input instead.
@@ -147,29 +147,29 @@ export function bind_group(inputs, group_index, input, get_value, update) {
 				value = hydration_input?.__value;
 			}
 
-			update(value);
+			set(value);
 		}
 	});
 }
 
 /**
  * @param {HTMLInputElement} input
- * @param {() => unknown} get_value
- * @param {(value: unknown) => void} update
+ * @param {() => unknown} get
+ * @param {(value: unknown) => void} set
  * @returns {void}
  */
-export function bind_checked(input, get_value, update) {
+export function bind_checked(input, get, set = get) {
 	listen_to_event_and_reset_event(input, 'change', () => {
 		var value = input.checked;
-		update(value);
+		set(value);
 	});
 
-	if (get_value() == undefined) {
-		update(false);
+	if (get() == undefined) {
+		set(false);
 	}
 
 	render_effect(() => {
-		var value = get_value();
+		var value = get();
 		input.checked = Boolean(value);
 	});
 }
@@ -215,15 +215,15 @@ function to_number(value) {
 
 /**
  * @param {HTMLInputElement} input
- * @param {() => FileList | null} get_value
- * @param {(value: FileList | null) => void} update
+ * @param {() => FileList | null} get
+ * @param {(value: FileList | null) => void} set
  */
-export function bind_files(input, get_value, update) {
+export function bind_files(input, get, set = get) {
 	listen_to_event_and_reset_event(input, 'change', () => {
-		update(input.files);
+		set(input.files);
 	});
 
 	render_effect(() => {
-		input.files = get_value();
+		input.files = get();
 	});
 }
diff --git a/packages/svelte/src/internal/client/dom/elements/bindings/media.js b/packages/svelte/src/internal/client/dom/elements/bindings/media.js
index 320e3856f2..ad955c89dc 100644
--- a/packages/svelte/src/internal/client/dom/elements/bindings/media.js
+++ b/packages/svelte/src/internal/client/dom/elements/bindings/media.js
@@ -15,11 +15,11 @@ function time_ranges_to_array(ranges) {
 
 /**
  * @param {HTMLVideoElement | HTMLAudioElement} media
- * @param {() => number | undefined} get_value
- * @param {(value: number) => void} update
+ * @param {() => number | undefined} get
+ * @param {(value: number) => void} set
  * @returns {void}
  */
-export function bind_current_time(media, get_value, update) {
+export function bind_current_time(media, get, set = get) {
 	/** @type {number} */
 	var raf_id;
 	/** @type {number} */
@@ -37,7 +37,7 @@ export function bind_current_time(media, get_value, update) {
 
 		var next_value = media.currentTime;
 		if (value !== next_value) {
-			update((value = next_value));
+			set((value = next_value));
 		}
 	};
 
@@ -45,7 +45,7 @@ export function bind_current_time(media, get_value, update) {
 	media.addEventListener('timeupdate', callback);
 
 	render_effect(() => {
-		var next_value = Number(get_value());
+		var next_value = Number(get());
 
 		if (value !== next_value && !isNaN(/** @type {any} */ (next_value))) {
 			media.currentTime = value = next_value;
@@ -57,66 +57,66 @@ export function bind_current_time(media, get_value, update) {
 
 /**
  * @param {HTMLVideoElement | HTMLAudioElement} media
- * @param {(array: Array<{ start: number; end: number }>) => void} update
+ * @param {(array: Array<{ start: number; end: number }>) => void} set
  */
-export function bind_buffered(media, update) {
-	listen(media, ['loadedmetadata', 'progress'], () => update(time_ranges_to_array(media.buffered)));
+export function bind_buffered(media, set) {
+	listen(media, ['loadedmetadata', 'progress'], () => set(time_ranges_to_array(media.buffered)));
 }
 
 /**
  * @param {HTMLVideoElement | HTMLAudioElement} media
- * @param {(array: Array<{ start: number; end: number }>) => void} update
+ * @param {(array: Array<{ start: number; end: number }>) => void} set
  */
-export function bind_seekable(media, update) {
-	listen(media, ['loadedmetadata'], () => update(time_ranges_to_array(media.seekable)));
+export function bind_seekable(media, set) {
+	listen(media, ['loadedmetadata'], () => set(time_ranges_to_array(media.seekable)));
 }
 
 /**
  * @param {HTMLVideoElement | HTMLAudioElement} media
- * @param {(array: Array<{ start: number; end: number }>) => void} update
+ * @param {(array: Array<{ start: number; end: number }>) => void} set
  */
-export function bind_played(media, update) {
-	listen(media, ['timeupdate'], () => update(time_ranges_to_array(media.played)));
+export function bind_played(media, set) {
+	listen(media, ['timeupdate'], () => set(time_ranges_to_array(media.played)));
 }
 
 /**
  * @param {HTMLVideoElement | HTMLAudioElement} media
- * @param {(seeking: boolean) => void} update
+ * @param {(seeking: boolean) => void} set
  */
-export function bind_seeking(media, update) {
-	listen(media, ['seeking', 'seeked'], () => update(media.seeking));
+export function bind_seeking(media, set) {
+	listen(media, ['seeking', 'seeked'], () => set(media.seeking));
 }
 
 /**
  * @param {HTMLVideoElement | HTMLAudioElement} media
- * @param {(seeking: boolean) => void} update
+ * @param {(seeking: boolean) => void} set
  */
-export function bind_ended(media, update) {
-	listen(media, ['timeupdate', 'ended'], () => update(media.ended));
+export function bind_ended(media, set) {
+	listen(media, ['timeupdate', 'ended'], () => set(media.ended));
 }
 
 /**
  * @param {HTMLVideoElement | HTMLAudioElement} media
- * @param {(ready_state: number) => void} update
+ * @param {(ready_state: number) => void} set
  */
-export function bind_ready_state(media, update) {
+export function bind_ready_state(media, set) {
 	listen(
 		media,
 		['loadedmetadata', 'loadeddata', 'canplay', 'canplaythrough', 'playing', 'waiting', 'emptied'],
-		() => update(media.readyState)
+		() => set(media.readyState)
 	);
 }
 
 /**
  * @param {HTMLVideoElement | HTMLAudioElement} media
- * @param {() => number | undefined} get_value
- * @param {(playback_rate: number) => void} update
+ * @param {() => number | undefined} get
+ * @param {(playback_rate: number) => void} set
  */
-export function bind_playback_rate(media, get_value, update) {
+export function bind_playback_rate(media, get, set = get) {
 	// Needs to happen after element is inserted into the dom (which is guaranteed by using effect),
 	// else playback will be set back to 1 by the browser
 	effect(() => {
-		var value = Number(get_value());
+		var value = Number(get());
 
 		if (value !== media.playbackRate && !isNaN(value)) {
 			media.playbackRate = value;
@@ -127,24 +127,24 @@ export function bind_playback_rate(media, get_value, update) {
 	// else playback will be set to 1 by the browser
 	effect(() => {
 		listen(media, ['ratechange'], () => {
-			update(media.playbackRate);
+			set(media.playbackRate);
 		});
 	});
 }
 
 /**
  * @param {HTMLVideoElement | HTMLAudioElement} media
- * @param {() => boolean | undefined} get_value
- * @param {(paused: boolean) => void} update
+ * @param {() => boolean | undefined} get
+ * @param {(paused: boolean) => void} set
  */
-export function bind_paused(media, get_value, update) {
+export function bind_paused(media, get, set = get) {
 	var mounted = hydrating;
-	var paused = get_value();
+	var paused = get();
 
 	var callback = () => {
 		if (paused !== media.paused) {
 			paused = media.paused;
-			update((paused = media.paused));
+			set((paused = media.paused));
 		}
 	};
 
@@ -160,7 +160,7 @@ export function bind_paused(media, get_value, update) {
 	}
 
 	render_effect(() => {
-		paused = !!get_value();
+		paused = !!get();
 
 		if (paused !== media.paused) {
 			var toggle = () => {
@@ -169,7 +169,7 @@ export function bind_paused(media, get_value, update) {
 					media.pause();
 				} else {
 					media.play().catch(() => {
-						update((paused = true));
+						set((paused = true));
 					});
 				}
 			};
@@ -195,22 +195,22 @@ export function bind_paused(media, get_value, update) {
 
 /**
  * @param {HTMLVideoElement | HTMLAudioElement} media
- * @param {() => number | undefined} get_value
- * @param {(volume: number) => void} update
+ * @param {() => number | undefined} get
+ * @param {(volume: number) => void} set
  */
-export function bind_volume(media, get_value, update) {
+export function bind_volume(media, get, set = get) {
 	var callback = () => {
-		update(media.volume);
+		set(media.volume);
 	};
 
-	if (get_value() == null) {
+	if (get() == null) {
 		callback();
 	}
 
 	listen(media, ['volumechange'], callback, false);
 
 	render_effect(() => {
-		var value = Number(get_value());
+		var value = Number(get());
 
 		if (value !== media.volume && !isNaN(value)) {
 			media.volume = value;
@@ -220,22 +220,22 @@ export function bind_volume(media, get_value, update) {
 
 /**
  * @param {HTMLVideoElement | HTMLAudioElement} media
- * @param {() => boolean | undefined} get_value
- * @param {(muted: boolean) => void} update
+ * @param {() => boolean | undefined} get
+ * @param {(muted: boolean) => void} set
  */
-export function bind_muted(media, get_value, update) {
+export function bind_muted(media, get, set = get) {
 	var callback = () => {
-		update(media.muted);
+		set(media.muted);
 	};
 
-	if (get_value() == null) {
+	if (get() == null) {
 		callback();
 	}
 
 	listen(media, ['volumechange'], callback, false);
 
 	render_effect(() => {
-		var value = !!get_value();
+		var value = !!get();
 
 		if (media.muted !== value) media.muted = value;
 	});
diff --git a/packages/svelte/src/internal/client/dom/elements/bindings/select.js b/packages/svelte/src/internal/client/dom/elements/bindings/select.js
index 5cd08a598e..4d3dbff812 100644
--- a/packages/svelte/src/internal/client/dom/elements/bindings/select.js
+++ b/packages/svelte/src/internal/client/dom/elements/bindings/select.js
@@ -73,11 +73,11 @@ export function init_select(select, get_value) {
 
 /**
  * @param {HTMLSelectElement} select
- * @param {() => unknown} get_value
- * @param {(value: unknown) => void} update
+ * @param {() => unknown} get
+ * @param {(value: unknown) => void} set
  * @returns {void}
  */
-export function bind_select_value(select, get_value, update) {
+export function bind_select_value(select, get, set = get) {
 	var mounting = true;
 
 	listen_to_event_and_reset_event(select, 'change', () => {
@@ -92,12 +92,12 @@ export function bind_select_value(select, get_value, update) {
 			value = selected_option && get_option_value(selected_option);
 		}
 
-		update(value);
+		set(value);
 	});
 
 	// Needs to be an effect, not a render_effect, so that in case of each loops the logic runs after the each block has updated
 	effect(() => {
-		var value = get_value();
+		var value = get();
 		select_option(select, value, mounting);
 
 		// Mounting and value undefined -> take selection from dom
@@ -106,7 +106,7 @@ export function bind_select_value(select, get_value, update) {
 			var selected_option = select.querySelector(':checked');
 			if (selected_option !== null) {
 				value = get_option_value(selected_option);
-				update(value);
+				set(value);
 			}
 		}
 
diff --git a/packages/svelte/src/internal/client/dom/elements/bindings/size.js b/packages/svelte/src/internal/client/dom/elements/bindings/size.js
index c817787497..a76c70aab1 100644
--- a/packages/svelte/src/internal/client/dom/elements/bindings/size.js
+++ b/packages/svelte/src/internal/client/dom/elements/bindings/size.js
@@ -78,9 +78,9 @@ var resize_observer_device_pixel_content_box = /* @__PURE__ */ new ResizeObserve
 /**
  * @param {Element} element
  * @param {'contentRect' | 'contentBoxSize' | 'borderBoxSize' | 'devicePixelContentBoxSize'} type
- * @param {(entry: keyof ResizeObserverEntry) => void} update
+ * @param {(entry: keyof ResizeObserverEntry) => void} set
  */
-export function bind_resize_observer(element, type, update) {
+export function bind_resize_observer(element, type, set) {
 	var observer =
 		type === 'contentRect' || type === 'contentBoxSize'
 			? resize_observer_content_box
@@ -88,21 +88,21 @@ export function bind_resize_observer(element, type, update) {
 				? resize_observer_border_box
 				: resize_observer_device_pixel_content_box;
 
-	var unsub = observer.observe(element, /** @param {any} entry */ (entry) => update(entry[type]));
+	var unsub = observer.observe(element, /** @param {any} entry */ (entry) => set(entry[type]));
 	teardown(unsub);
 }
 
 /**
  * @param {HTMLElement} element
  * @param {'clientWidth' | 'clientHeight' | 'offsetWidth' | 'offsetHeight'} type
- * @param {(size: number) => void} update
+ * @param {(size: number) => void} set
  */
-export function bind_element_size(element, type, update) {
-	var unsub = resize_observer_border_box.observe(element, () => update(element[type]));
+export function bind_element_size(element, type, set) {
+	var unsub = resize_observer_border_box.observe(element, () => set(element[type]));
 
 	effect(() => {
 		// The update could contain reads which should be ignored
-		untrack(() => update(element[type]));
+		untrack(() => set(element[type]));
 		return unsub;
 	});
 }
diff --git a/packages/svelte/src/internal/client/dom/elements/bindings/universal.js b/packages/svelte/src/internal/client/dom/elements/bindings/universal.js
index bb00e09da6..5b10abdc4c 100644
--- a/packages/svelte/src/internal/client/dom/elements/bindings/universal.js
+++ b/packages/svelte/src/internal/client/dom/elements/bindings/universal.js
@@ -4,24 +4,24 @@ import { listen } from './shared.js';
 /**
  * @param {'innerHTML' | 'textContent' | 'innerText'} property
  * @param {HTMLElement} element
- * @param {() => unknown} get_value
- * @param {(value: unknown) => void} update
+ * @param {() => unknown} get
+ * @param {(value: unknown) => void} set
  * @returns {void}
  */
-export function bind_content_editable(property, element, get_value, update) {
+export function bind_content_editable(property, element, get, set = get) {
 	element.addEventListener('input', () => {
 		// @ts-ignore
-		update(element[property]);
+		set(element[property]);
 	});
 
 	render_effect(() => {
-		var value = get_value();
+		var value = get();
 
 		if (element[property] !== value) {
 			if (value == null) {
 				// @ts-ignore
 				var non_null_value = element[property];
-				update(non_null_value);
+				set(non_null_value);
 			} else {
 				// @ts-ignore
 				element[property] = value + '';
@@ -65,11 +65,11 @@ export function bind_property(property, event_name, element, set, get) {
 
 /**
  * @param {HTMLElement} element
- * @param {(value: unknown) => void} update
+ * @param {(value: unknown) => void} set
  * @returns {void}
  */
-export function bind_focused(element, update) {
+export function bind_focused(element, set) {
 	listen(element, ['focus', 'blur'], () => {
-		update(element === document.activeElement);
+		set(element === document.activeElement);
 	});
 }
diff --git a/packages/svelte/src/internal/client/dom/elements/bindings/window.js b/packages/svelte/src/internal/client/dom/elements/bindings/window.js
index 23f594a0fe..61775b9d4b 100644
--- a/packages/svelte/src/internal/client/dom/elements/bindings/window.js
+++ b/packages/svelte/src/internal/client/dom/elements/bindings/window.js
@@ -3,11 +3,11 @@ import { listen } from './shared.js';
 
 /**
  * @param {'x' | 'y'} type
- * @param {() => number} get_value
- * @param {(value: number) => void} update
+ * @param {() => number} get
+ * @param {(value: number) => void} set
  * @returns {void}
  */
-export function bind_window_scroll(type, get_value, update) {
+export function bind_window_scroll(type, get, set = get) {
 	var is_scrolling_x = type === 'x';
 
 	var target_handler = () => {
@@ -15,7 +15,7 @@ export function bind_window_scroll(type, get_value, update) {
 		clearTimeout(timeout);
 		timeout = setTimeout(clear, 100); // TODO use scrollend event if supported (or when supported everywhere?)
 
-		update(window[is_scrolling_x ? 'scrollX' : 'scrollY']);
+		set(window[is_scrolling_x ? 'scrollX' : 'scrollY']);
 	};
 
 	addEventListener('scroll', target_handler, {
@@ -32,7 +32,7 @@ export function bind_window_scroll(type, get_value, update) {
 	var first = true;
 
 	render_effect(() => {
-		var latest_value = get_value();
+		var latest_value = get();
 		// Don't scroll to the initial value for accessibility reasons
 		if (first) {
 			first = false;
@@ -58,8 +58,8 @@ export function bind_window_scroll(type, get_value, update) {
 
 /**
  * @param {'innerWidth' | 'innerHeight' | 'outerWidth' | 'outerHeight'} type
- * @param {(size: number) => void} update
+ * @param {(size: number) => void} set
  */
-export function bind_window_size(type, update) {
-	listen(window, ['resize'], () => update(window[type]));
+export function bind_window_size(type, set) {
+	listen(window, ['resize'], () => set(window[type]));
 }