diff --git a/src/main/native-chat/wsl-transcript-fs-process-spawn.test.ts b/src/main/native-chat/wsl-transcript-fs-process-spawn.test.ts
new file mode 100644
index 00000000000..8547ad2e601
--- /dev/null
+++ b/src/main/native-chat/wsl-transcript-fs-process-spawn.test.ts
@@ -0,0 +1,46 @@
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import { forkWslTranscriptFsProcess } from './wsl-transcript-fs-process-spawn'
+
+const fork = vi.hoisted(() => vi.fn())
+vi.mock('node:child_process', () => ({ fork }))
+vi.mock('node:fs', () => ({ existsSync: () => true }))
+
+afterEach(() => {
+  vi.unstubAllGlobals()
+  vi.clearAllMocks()
+})
+
+describe('WSL transcript reader runtime isolation', () => {
+  it.each(['darwin', 'linux', 'win32'])('isolates owned Bun reads on %s', (platform) => {
+    vi.stubGlobal('process', {
+      ...process,
+      platform,
+      versions: { ...process.versions, bun: '1.4.2' }
+    })
+    forkWslTranscriptFsProcess()
+    expect(fork).toHaveBeenCalledWith(
+      expect.any(String),
+      [],
+      expect.objectContaining({
+        execArgv: [
+          '--no-env-file',
+          platform === 'win32' ? '--config=NUL' : '--config=/dev/null',
+          '--no-install'
+        ]
+      })
+    )
+  })
+
+  it('preserves the Node and Electron launch policy', () => {
+    vi.stubGlobal('process', { ...process, versions: { ...process.versions, bun: undefined } })
+    forkWslTranscriptFsProcess()
+    expect(fork).toHaveBeenCalledWith(
+      expect.any(String),
+      [],
+      expect.objectContaining({
+        execArgv: [],
+        env: expect.objectContaining({ ELECTRON_RUN_AS_NODE: '1' })
+      })
+    )
+  })
+})
diff --git a/src/main/native-chat/wsl-transcript-fs-process-spawn.ts b/src/main/native-chat/wsl-transcript-fs-process-spawn.ts
index 5d67cba8bed..7b7fcd8b0cb 100644
--- a/src/main/native-chat/wsl-transcript-fs-process-spawn.ts
+++ b/src/main/native-chat/wsl-transcript-fs-process-spawn.ts
@@ -1,6 +1,7 @@
 import { fork, type ChildProcess } from 'node:child_process'
 import { existsSync } from 'node:fs'
 import { join } from 'node:path'
+import { bunOwnedRuntimeArgs } from '../../shared/bun-owned-runtime-args'
 import { pickAllowedEnv, RUNTIME_ENV_ALLOWLIST } from '../ai-vault/session-scanner-service-env'
 
 const PROCESS_ENTRY_FILENAME = 'wsl-transcript-fs-process-entry.js'
@@ -50,7 +51,7 @@ export function forkWslTranscriptFsProcess(): ChildProcess {
   }
   return fork(entryPath, [], {
     env: wslTranscriptFsProcessForkEnv(),
-    execArgv: [],
+    execArgv: process.versions.bun ? bunOwnedRuntimeArgs() : [],
     serialization: 'advanced',
     stdio: ['ignore', 'ignore', 'ignore', 'ipc'],
     ...(process.platform === 'win32' ? { windowsHide: true } : {})