diff --git a/src/renderer/src/components/editor/useEditorPanelContentState.ts b/src/renderer/src/components/editor/useEditorPanelContentState.ts
index 7d76617b708..14a4375d196 100644
--- a/src/renderer/src/components/editor/useEditorPanelContentState.ts
+++ b/src/renderer/src/components/editor/useEditorPanelContentState.ts
@@ -1,7 +1,7 @@
 /* oxlint-disable max-lines -- Why: content loading, retry, and external-change
    subscriptions share in-flight caches and state setters; splitting them would
    make the hook coordination harder to audit. */
-import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
+import { useCallback, useEffect, useLayoutEffect, useMemo, useRef, useState } from 'react'
 import type { OpenFile } from '@/store/slices/editor'
 import { getConnectionIdForFile, isWorktreeConnectionResolved } from '@/lib/connection-context'
 import { joinPath } from '@/lib/path'
@@ -133,7 +133,7 @@ export function useEditorPanelContentState({
   const activeContentFileId = selectedConflictReviewFile?.id ?? activeFile?.id ?? null
   const activeContentFileIdRef = useRef(activeContentFileId)
 
-  useEffect(() => {
+  useLayoutEffect(() => {
     // Why: event-driven readers must only observe state from committed renders.
     diffContentsRef.current = diffContents
     openFilesRef.current = openFiles
diff --git a/src/renderer/src/components/editor/useEditorPanelExternalContentEvents.test.tsx b/src/renderer/src/components/editor/useEditorPanelExternalContentEvents.test.tsx
index a7d9db6b968..12f5471e54c 100644
--- a/src/renderer/src/components/editor/useEditorPanelExternalContentEvents.test.tsx
+++ b/src/renderer/src/components/editor/useEditorPanelExternalContentEvents.test.tsx
@@ -1,6 +1,6 @@
 // @vitest-environment happy-dom
 
-import { act, useEffect, useRef, useState } from 'react'
+import { act, useLayoutEffect, useRef, useState } from 'react'
 import { createRoot, type Root } from 'react-dom/client'
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 import type { OpenFile } from '@/store/slices/editor'
@@ -30,7 +30,7 @@ function ExternalContentProbe({ activeFileId, calls, isVisible, openFiles }: Pro
   const [, setFileContents] = useState<Record<string, FileContent>>({})
   const [, setDiffContents] = useState<Record<string, DiffContent>>({})
 
-  useEffect(() => {
+  useLayoutEffect(() => {
     activeContentFileIdRef.current = activeFileId
     isVisibleRef.current = isVisible
     openFilesRef.current = openFiles