diff --git a/packages/svelte/src/internal/client/reactivity/effects.js b/packages/svelte/src/internal/client/reactivity/effects.js
index a4e0ff21c9..68a1555032 100644
--- a/packages/svelte/src/internal/client/reactivity/effects.js
+++ b/packages/svelte/src/internal/client/reactivity/effects.js
@@ -407,9 +407,13 @@ export function destroy_effect_children(signal, remove_dom = false) {
 	signal.first = signal.last = null;
 
 	while (effect !== null) {
-		without_reactive_context(() => {
-			/** @type {Effect} */ (effect).ac?.abort(STALE_REACTION);
-		});
+		const controller = effect.ac;
+
+		if (controller !== null) {
+			without_reactive_context(() => {
+				controller.abort(STALE_REACTION);
+			});
+		}
 
 		var next = effect.next;
 
diff --git a/packages/svelte/src/internal/client/runtime.js b/packages/svelte/src/internal/client/runtime.js
index fe46461b16..22a1890e0f 100644
--- a/packages/svelte/src/internal/client/runtime.js
+++ b/packages/svelte/src/internal/client/runtime.js
@@ -282,6 +282,7 @@ export function update_reaction(reaction) {
 		without_reactive_context(() => {
 			/** @type {AbortController} */ (reaction.ac).abort(STALE_REACTION);
 		});
+
 		reaction.ac = null;
 	}