diff --git a/packages/svelte/src/internal/client/dom/blocks/async.js b/packages/svelte/src/internal/client/dom/blocks/async.js
index db6a7fda79..c3283081ab 100644
--- a/packages/svelte/src/internal/client/dom/blocks/async.js
+++ b/packages/svelte/src/internal/client/dom/blocks/async.js
@@ -3,7 +3,7 @@
 import { async_derived } from '../../reactivity/deriveds.js';
 import { current_batch } from '../../reactivity/batch.js';
 import { active_effect, schedule_effect } from '../../runtime.js';
-import { capture } from './boundary.js';
+import { capture, get_pending_boundary } from './boundary.js';
 
 /**
  * @param {TemplateNode} node
@@ -15,19 +15,10 @@ export function async(node, expressions, fn) {
 
 	var batch = /** @type {Batch} */ (current_batch);
 	var effect = /** @type {Effect} */ (active_effect);
+	var boundary = get_pending_boundary(effect);
 
 	var restore = capture();
 
-	let boundary = effect.b;
-
-	while (boundary !== null && !boundary.has_pending_snippet()) {
-		boundary = boundary.parent;
-	}
-
-	if (boundary === null) {
-		throw new Error('TODO cannot create async derived outside a boundary with a pending snippet');
-	}
-
 	boundary.increment();
 
 	Promise.all(expressions.map((fn) => async_derived(fn))).then((result) => {
diff --git a/packages/svelte/src/internal/client/dom/blocks/boundary.js b/packages/svelte/src/internal/client/dom/blocks/boundary.js
index a98a354bd0..2f7c0d2e4d 100644
--- a/packages/svelte/src/internal/client/dom/blocks/boundary.js
+++ b/packages/svelte/src/internal/client/dom/blocks/boundary.js
@@ -327,6 +327,21 @@ function move_effect(effect, fragment) {
 	}
 }
 
+/** @param {Effect} effect */
+export function get_pending_boundary(effect) {
+	let boundary = effect.b;
+
+	while (boundary !== null && !boundary.has_pending_snippet()) {
+		boundary = boundary.parent;
+	}
+
+	if (boundary === null) {
+		e.await_outside_boundary();
+	}
+
+	return boundary;
+}
+
 export function capture(track = true) {
 	var previous_effect = active_effect;
 	var previous_reaction = active_reaction;
@@ -352,20 +367,7 @@ export function capture(track = true) {
 
 // TODO we should probably be incrementing the current batch, not the boundary?
 export function suspend() {
-	let boundary = /** @type {Effect} */ (active_effect).b;
-
-	while (boundary !== null) {
-		// TODO pretty sure this is wrong
-		if (boundary.has_pending_snippet()) {
-			break;
-		}
-
-		boundary = boundary.parent;
-	}
-
-	if (boundary === null) {
-		e.await_outside_boundary();
-	}
+	let boundary = get_pending_boundary(/** @type {Effect} */ (active_effect));
 
 	boundary.increment();
 
diff --git a/packages/svelte/src/internal/client/reactivity/deriveds.js b/packages/svelte/src/internal/client/reactivity/deriveds.js
index 314595c937..5c33a827dd 100644
--- a/packages/svelte/src/internal/client/reactivity/deriveds.js
+++ b/packages/svelte/src/internal/client/reactivity/deriveds.js
@@ -29,7 +29,7 @@ import { destroy_effect, render_effect } from './effects.js';
 import { inspect_effects, internal_set, set_inspect_effects, source } from './sources.js';
 import { get_stack } from '../dev/tracing.js';
 import { tracing_mode_flag } from '../../flags/index.js';
-import { capture } from '../dom/blocks/boundary.js';
+import { capture, get_pending_boundary } from '../dom/blocks/boundary.js';
 import { component_context } from '../context.js';
 import { UNINITIALIZED } from '../../../constants.js';
 import { current_batch } from './batch.js';
@@ -101,15 +101,7 @@ export function async_derived(fn, location) {
 		throw new Error('TODO cannot create unowned async derived');
 	}
 
-	let boundary = parent.b;
-
-	while (boundary !== null && !boundary.has_pending_snippet()) {
-		boundary = boundary.parent;
-	}
-
-	if (boundary === null) {
-		throw new Error('TODO cannot create async derived outside a boundary with a pending snippet');
-	}
+	let boundary = get_pending_boundary(parent);
 
 	var promise = /** @type {Promise<V>} */ (/** @type {unknown} */ (undefined));
 	var signal = source(/** @type {V} */ (UNINITIALIZED));