From f32818cfedef4f9b1744175027941e6aac46026b Mon Sep 17 00:00:00 2001
From: Rich Harris <rich.harris@vercel.com>
Date: Tue, 1 Jul 2025 15:25:00 -0400
Subject: [PATCH] easier debugging

---
 packages/svelte/src/internal/client/reactivity/deriveds.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/svelte/src/internal/client/reactivity/deriveds.js b/packages/svelte/src/internal/client/reactivity/deriveds.js
index d3123d24a1..37e8643e16 100644
--- a/packages/svelte/src/internal/client/reactivity/deriveds.js
+++ b/packages/svelte/src/internal/client/reactivity/deriveds.js
@@ -19,6 +19,7 @@ import { inspect_effects, set_inspect_effects } from './sources.js';
 import { get_stack } from '../dev/tracing.js';
 import { tracing_mode_flag } from '../../flags/index.js';
 import { component_context } from '../context.js';
+import { UNINITIALIZED } from '../../../constants.js';
 
 /**
  * @template V
@@ -51,7 +52,7 @@ export function derived(fn) {
 		fn,
 		reactions: null,
 		rv: 0,
-		v: /** @type {V} */ (null),
+		v: /** @type {V} */ (UNINITIALIZED),
 		wv: 0,
 		parent: parent_derived ?? active_effect,
 		ac: null