diff --git a/src/main/git/worktrees/removal/remove-worktree-clean-preflight.test.ts b/src/main/git/worktrees/removal/remove-worktree-clean-preflight.test.ts
index b891958bae4..1b454e6564d 100644
--- a/src/main/git/worktrees/removal/remove-worktree-clean-preflight.test.ts
+++ b/src/main/git/worktrees/removal/remove-worktree-clean-preflight.test.ts
@@ -7,14 +7,16 @@ const {
   translateWslOutputPathsMock,
   statMock,
   readFileMock,
-  resolveGitDirMock
+  resolveGitDirMock,
+  gitStreamStdoutMock
 } = vi.hoisted(() => ({
   gitExecFileAsyncMock: vi.fn(),
   gitExecFileSyncMock: vi.fn(),
   translateWslOutputPathsMock: vi.fn((output: string) => output),
   statMock: vi.fn(),
   readFileMock: vi.fn(),
-  resolveGitDirMock: vi.fn()
+  resolveGitDirMock: vi.fn(),
+  gitStreamStdoutMock: vi.fn()
 }))
 
 vi.mock('../../command-runner/git-exec-file', async (importOriginal) => ({
@@ -22,6 +24,10 @@ vi.mock('../../command-runner/git-exec-file', async (importOriginal) => ({
   gitExecFileAsync: gitExecFileAsyncMock
 }))
 
+vi.mock('../../command-runner/git-stream-stdout', () => ({
+  gitStreamStdout: gitStreamStdoutMock
+}))
+
 vi.mock('../../command-runner/git-exec-file-sync', async (importOriginal) => ({
   ...(await importOriginal<Record<string, unknown>>()),
   gitExecFileSync: gitExecFileSyncMock
@@ -56,10 +62,9 @@ beforeEach(() => {
 
 describe('assertWorktreeCleanForRemoval', () => {
   beforeEach(() => {
-    // Calls after the status read are the submodule probe's `ls-files`; failing leaves the verdict to Git.
-    gitExecFileAsyncMock
-      .mockReset()
-      .mockRejectedValue(new Error('git ls-files exited with code 128'))
+    gitExecFileAsyncMock.mockReset()
+    // A failed submodule probe leaves the verdict to Git.
+    gitStreamStdoutMock.mockReset().mockRejectedValue(new Error('git exited with 128: '))
   })
 
   it('ignores configured linked paths without mutating them before preflight', async () => {
diff --git a/src/main/git/worktrees/removal/worktree-removal-preflight.ts b/src/main/git/worktrees/removal/worktree-removal-preflight.ts
index dc6af37e7bb..65fff520b74 100644
--- a/src/main/git/worktrees/removal/worktree-removal-preflight.ts
+++ b/src/main/git/worktrees/removal/worktree-removal-preflight.ts
@@ -6,6 +6,7 @@ import {
   SUBMODULE_REMOVAL_REFUSAL
 } from '../../../../shared/worktree/removal/removal'
 import { gitExecFileAsync } from '../../command-runner/git-exec-file'
+import { gitStreamStdout } from '../../command-runner/git-stream-stdout'
 import { resolveGitDir } from '../../source-control/resolve-git-dir'
 import type { WorktreeRemovalPreflightOptions } from '../worktree-operation-options'
 import {
@@ -92,20 +93,46 @@ async function containsSubmoduleCheckout(
   if (adminDirectory && !(await isWorktreePathMissing(join(adminDirectory, 'modules')))) {
     return true
   }
-  const { stdout: index } = await gitExecFileAsync(['ls-files', '--stage', '-z'], execution)
-  for (const entry of index.split('\0')) {
-    if (
-      entry.startsWith('160000 ') &&
-      !(await isWorktreePathMissing(
-        join(hostWorktreePath, entry.slice(entry.indexOf('\t') + 1), '.git')
-      ))
-    ) {
+  for (const gitlink of await readGitlinkPaths(execution)) {
+    if (!(await isWorktreePathMissing(join(hostWorktreePath, gitlink, '.git')))) {
       return true
     }
   }
   return false
 }
 
+/** Stream the index keeping only gitlinks; a large repository's full listing exceeds the buffered cap. */
+async function readGitlinkPaths(
+  execution: Parameters<typeof gitExecFileAsync>[1]
+): Promise<string[]> {
+  const { cwd, env, wslDistro, signal, admissionTier, timeout } = execution
+  const gitlinks: string[] = []
+  const keepGitlink = (entry: string): void => {
+    if (entry.startsWith('160000 ')) {
+      gitlinks.push(entry.slice(entry.indexOf('\t') + 1))
+    }
+  }
+  let carry = ''
+  await gitStreamStdout(['ls-files', '--stage', '-z'], {
+    cwd,
+    env,
+    wslDistro,
+    signal,
+    admissionTier,
+    timeoutMs: timeout,
+    // Only gitlink paths are retained, so index size is not a memory risk.
+    maxBuffer: Number.MAX_SAFE_INTEGER,
+    maxStderrBuffer: 64 * 1024,
+    onStdout: (chunk) => {
+      const entries = (carry + chunk).split('\0')
+      carry = entries.pop() ?? ''
+      entries.forEach(keepGitlink)
+    }
+  })
+  keepGitlink(carry)
+  return gitlinks
+}
+
 /** Exclude only the untracked shared links tolerated by the caller. */
 function getBlockingUntrackedStatusEntries(
   status: string,
diff --git a/src/main/git/worktrees/removal/worktree-removal-real-git.test.ts b/src/main/git/worktrees/removal/worktree-removal-real-git.test.ts
index 763e20f94de..10bff011570 100644
--- a/src/main/git/worktrees/removal/worktree-removal-real-git.test.ts
+++ b/src/main/git/worktrees/removal/worktree-removal-real-git.test.ts
@@ -13,6 +13,7 @@ import { removeTree } from '../../../../shared/windows-transient-lock-removal'
 
 import { listWorktreesStrict } from '../catalog/worktree-listing'
 import { removeWorktree } from './worktree-removal'
+import { assertWorktreeCleanForRemoval } from './worktree-removal-preflight'
 import { areWorktreePathsEqual } from '../catalog/worktree-path-comparison'
 import { isPrunableGitFileWorktree } from '../../../workspaces/removal/worktree-prunable-git-file'
 import { removeStaleLocalWorktreeRegistration } from '../../../workspaces/removal/local-worktree-removal-recovery'
@@ -146,6 +147,31 @@ describe('worktree removal against the real Git binary', () => {
     expect(await isRegistered(subWorktreePath)).toBe(false)
   })
 
+  // Builds a ~48k-entry real Git index (>10 MiB of ls-files output), which is slow on Windows runners.
+  it('finds a checked-out submodule in an index listing larger than the Git output buffer', async () => {
+    const blob = (await git(['hash-object', '-w', 'seed.txt'], worktreePath)).trim()
+    const head = (await git(['rev-parse', 'HEAD'], worktreePath)).trim()
+    const entries = Array.from(
+      { length: 48_000 },
+      (_, i) => `100644 ${blob}\t${'nested-directory/'.repeat(12)}file-${i}.txt\n`
+    )
+    // Sorts last, so the gitlink is only seen after more than 10 MiB of listing.
+    entries.push(`160000 ${head}\tzz-vendor\n`)
+    const indexInfo = execFileAsync('git', ['update-index', '--index-info'], { cwd: worktreePath })
+    indexInfo.child.stdin?.end(entries.join(''))
+    await indexInfo
+    await mkdir(join(worktreePath, 'zz-vendor', '.git'), { recursive: true })
+
+    await expect(
+      assertWorktreeCleanForRemoval(
+        worktreePath,
+        false,
+        {},
+        join(repoPath, '.git', 'worktrees', 'feature')
+      )
+    ).rejects.toThrow('Worktree has uncommitted or untracked changes, and it contains submodules.')
+  }, 60_000)
+
   it('prunes a proven malformed registration while retaining checkout files and its branch', async () => {
     const markerPath = join(worktreePath, '.git')
     const marker = await readFile(markerPath, 'utf8')