diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3aee3765e4..9dfbf6e62c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2404,6 +2404,12 @@ This release closes that milestone with **772 merged pull requests**.
 
 ### Fixed
 
+- **dev:** `make stop` / `make dev` can now reclaim dev ports held by a sibling
+  worktree whose path contains spaces. `serve.sh` built its worktree-root list
+  with `awk '{print $2}'` over `git worktree list --porcelain`, whose paths are
+  unquoted, so `.../deer flow two` was recorded as `.../deer`; a Gateway or
+  frontend started from that worktree was never recognised as deer-flow's and
+  the start aborted with "port already in use". The whole path is kept now. ([#5856])
 - **uploads:** A malformed `files[*].size` in a run's message metadata no
   longer fails the whole run. `UploadsMiddleware` validated every other field
   of a client-supplied file entry fail-soft but passed `size` straight to
@@ -6086,5 +6092,6 @@ with **180 merged pull requests** since the first 2.0 milestone tag.
 [#5845]: https://github.com/bytedance/deer-flow/pull/5845
 [#5848]: https://github.com/bytedance/deer-flow/pull/5848
 [#5855]: https://github.com/bytedance/deer-flow/pull/5855
+[#5856]: https://github.com/bytedance/deer-flow/pull/5856
 [#5859]: https://github.com/bytedance/deer-flow/pull/5859
 
diff --git a/CHANGELOG_zh.md b/CHANGELOG_zh.md
index fbc0cbeeca..76023f95f1 100644
--- a/CHANGELOG_zh.md
+++ b/CHANGELOG_zh.md
@@ -2120,6 +2120,11 @@
 
 ### 修复
 
+- **开发：** 当同级 worktree 的路径包含空格时，`make stop` / `make dev` 现在也能回收它占用的
+  开发端口。`serve.sh` 用 `awk '{print $2}'` 解析 `git worktree list --porcelain` 来构建
+  worktree 根目录列表，而该输出中的路径不加引号，因此 `.../deer flow two` 被记录成了
+  `.../deer`；从那个 worktree 启动的 Gateway 或前端永远不会被识别为 deer-flow 的进程，
+  启动会以“端口已被占用”中止。现在会保留整条路径。([#5856])
 - **上传：** 运行消息元数据中格式错误的 `files[*].size` 不再导致整个运行失败。
   `UploadsMiddleware` 对客户端提供的文件条目的其他字段都做了容错校验，唯独把 `size` 直接交给
   `int()`，因此 `"abc"` 或列表这样的值会在调用模型之前从 `before_agent` 抛出——而且由于该条目
@@ -5181,4 +5186,5 @@ DeerFlow 2.0 是围绕"超级智能体"框架的彻底重写，核心包含子
 [#5845]: https://github.com/bytedance/deer-flow/pull/5845
 [#5848]: https://github.com/bytedance/deer-flow/pull/5848
 [#5855]: https://github.com/bytedance/deer-flow/pull/5855
+[#5856]: https://github.com/bytedance/deer-flow/pull/5856
 [#5859]: https://github.com/bytedance/deer-flow/pull/5859
diff --git a/backend/tests/test_serve_worktree_roots.py b/backend/tests/test_serve_worktree_roots.py
new file mode 100644
index 0000000000..17d7ea5330
--- /dev/null
+++ b/backend/tests/test_serve_worktree_roots.py
@@ -0,0 +1,80 @@
+"""``scripts/serve.sh`` must discover every deer-flow worktree root verbatim.
+
+``DEERFLOW_ROOTS`` is the set of checkout roots whose dev-port holders
+``make stop`` / ``make dev`` may reclaim. It is built from
+``git worktree list --porcelain``, whose ``worktree <path>`` lines are not
+quoted, so a root containing whitespace must be taken as the whole remainder
+of the line — ``awk '{print $2}'`` keeps only the first word, and a sibling
+worktree at ``.../deer flow two`` was recorded as ``.../deer``, which
+``_is_deerflow_pid`` can never match.
+"""
+
+from __future__ import annotations
+
+import os
+import shlex
+import subprocess
+from pathlib import Path
+
+import pytest
+from support.shell import require_script_bash
+
+REPO_ROOT = Path(__file__).resolve().parents[2]
+SERVE_SH = REPO_ROOT / "scripts" / "serve.sh"
+
+pytestmark = pytest.mark.skipif(os.name == "nt", reason="exercises git worktree paths through a POSIX shell")
+
+
+def _extract_deerflow_roots_block() -> str:
+    text = SERVE_SH.read_text(encoding="utf-8")
+    start = text.index('DEERFLOW_ROOTS="$(')
+    chunks: list[str] = []
+    for line in text[start:].splitlines(keepends=True):
+        chunks.append(line)
+        if line.rstrip("\n") == ')"':
+            return "".join(chunks)
+    raise AssertionError("Could not extract the DEERFLOW_ROOTS block from serve.sh")
+
+
+def _git(*args: str, cwd: Path) -> None:
+    subprocess.run(["git", *args], cwd=cwd, check=True, capture_output=True, env={**os.environ, "GIT_CONFIG_GLOBAL": os.devnull})
+
+
+def _repo_with_spaced_worktree(tmp_path: Path) -> tuple[Path, Path]:
+    main = tmp_path / "deer-flow"
+    main.mkdir()
+    _git("init", "-q", cwd=main)
+    _git("-c", "user.email=t@example.com", "-c", "user.name=t", "commit", "-q", "--allow-empty", "-m", "init", cwd=main)
+    linked = tmp_path / "deer flow two"
+    _git("worktree", "add", "-q", str(linked), "-b", "wt-two", cwd=main)
+    return main.resolve(), linked.resolve()
+
+
+def _deerflow_roots(repo_root: Path) -> list[str]:
+    bash = require_script_bash()
+    script = f"""
+REPO_ROOT={shlex.quote(str(repo_root))}
+{_extract_deerflow_roots_block()}
+printf '%s\\n' "$DEERFLOW_ROOTS"
+"""
+    result = subprocess.run([bash, "-c", script], check=True, capture_output=True, text=True)
+    return [line for line in result.stdout.splitlines() if line]
+
+
+def test_worktree_root_with_spaces_is_kept_whole(tmp_path):
+    main, linked = _repo_with_spaced_worktree(tmp_path)
+
+    roots = _deerflow_roots(main)
+
+    assert str(linked) in roots
+    assert all(Path(root).is_dir() for root in roots), roots  # no truncated fragment such as ".../deer"
+    assert sorted(roots, key=len, reverse=True) == roots  # most-specific (longest) root first
+
+
+def test_repo_root_with_spaces_is_listed_once(tmp_path):
+    main, linked = _repo_with_spaced_worktree(tmp_path)
+
+    roots = _deerflow_roots(linked)  # the checkout we run from is itself the spaced path
+
+    assert roots.count(str(linked)) == 1
+    assert set(roots) == {str(main), str(linked)}  # and no truncated fragment alongside them
diff --git a/scripts/serve.sh b/scripts/serve.sh
index f1e3968c47..1cc3f9f76c 100755
--- a/scripts/serve.sh
+++ b/scripts/serve.sh
@@ -98,7 +98,7 @@ DEERFLOW_ROOTS="$(
     {
         printf '%s\n' "$REPO_ROOT"
         git -C "$REPO_ROOT" worktree list --porcelain 2>/dev/null |
-            awk '/^worktree /{print $2}'
+            awk '/^worktree /{sub(/^worktree /, ""); print}'  # whole line: paths are unquoted and may contain spaces
     } | awk 'NF && !seen[$0]++ {print length($0)"\t"$0}' | sort -rn | sed 's/^[0-9]*\t//'
 )"