diff --git a/probhub/mutation_parser_worker.py b/probhub/mutation_parser_worker.py
index 33b8e21..62dc2a8 100644
--- a/probhub/mutation_parser_worker.py
+++ b/probhub/mutation_parser_worker.py
@@ -163,38 +163,153 @@ def span(self, node):
         }
 
 
-def _parse_cpp(source_bytes):
+def _new_cpp_parser():
     try:
         from tree_sitter import Parser
         from tree_sitter import Language
         import tree_sitter_cpp
 
         language = Language(tree_sitter_cpp.language())
-        tree = Parser(language).parse(source_bytes)
+        return Parser(language)
     except ImportError as exc:
         raise RuntimeError(f"mutation parser dependencies are unavailable: {exc}") from exc
     except (TypeError, ValueError, RuntimeError) as exc:
         raise RuntimeError(f"C++ mutation parser failed: {exc}") from exc
+
+
+def _parse_tree(parser, source_bytes):
+    try:
+        tree = parser.parse(source_bytes)
+    except (TypeError, ValueError, RuntimeError) as exc:
+        raise RuntimeError(f"C++ mutation parser failed: {exc}") from exc
     if tree is None or tree.root_node is None:
         raise RuntimeError("C++ mutation parser returned no syntax tree")
-    if tree.root_node.has_error:
-        error = _first_syntax_error(tree.root_node)
-        point = error.start_point if error is not None else tree.root_node.start_point
-        raise SyntaxError(
-            "accepted C++ source contains syntax the mutation parser cannot locate safely "
-            f"at line {point.row + 1}, byte column {point.column + 1}"
-        )
     return tree
 
 
-def _first_syntax_error(node):
+def _syntax_issues(node):
+    issues = []
     stack = [node]
     while stack:
         current = stack.pop()
         if current.type == "ERROR" or current.is_missing:
-            return current
+            issues.append(current)
         stack.extend(reversed(current.children))
-    return None
+    return issues
+
+
+def _raise_syntax_error(root):
+    issues = _syntax_issues(root)
+    error = issues[0] if issues else root
+    point = error.start_point
+    raise SyntaxError(
+        "accepted C++ source contains syntax the mutation parser cannot locate safely "
+        f"at line {point.row + 1}, byte column {point.column + 1}"
+    )
+
+
+def _enclosing_typeid_argument(issue, source_bytes):
+    argument = issue
+    while argument is not None:
+        if argument.type == "argument_list" and argument.parent is not None:
+            call = argument.parent
+            if call.type == "call_expression":
+                function = call.child_by_field_name("function")
+                arguments = call.child_by_field_name("arguments")
+                if (
+                    function is not None
+                    and function.type == "identifier"
+                    and arguments is not None
+                    and arguments.id == argument.id
+                    and source_bytes[function.start_byte:function.end_byte] == b"typeid"
+                ):
+                    break
+        argument = argument.parent
+    if argument is None:
+        return None
+    children = argument.children
+    if len(children) < 2:
+        return None
+    opening = children[0]
+    closing = children[-1]
+    if (
+        opening.type != "("
+        or closing.type != ")"
+        or opening.is_missing
+        or closing.is_missing
+        or opening.start_byte != argument.start_byte
+        or closing.end_byte != argument.end_byte
+        or source_bytes[opening.start_byte:opening.end_byte] != b"("
+        or source_bytes[closing.start_byte:closing.end_byte] != b")"
+    ):
+        return None
+    return opening.end_byte, closing.start_byte
+
+
+def _valid_type_id(parser, type_id):
+    # The pinned grammar parses aliases correctly even when it rejects the
+    # same type-id inside typeid(...), so use a single-declaration probe.
+    prefix = b"using __probhub_type = "
+    probe = prefix + type_id + b";"
+    tree = _parse_tree(parser, probe)
+    if tree.root_node.has_error:
+        return False
+    meaningful = [
+        child for child in tree.root_node.named_children
+        if child.type != "comment"
+    ]
+    if len(meaningful) != 1 or meaningful[0].type != "alias_declaration":
+        return False
+    declaration = meaningful[0]
+    name = declaration.child_by_field_name("name")
+    descriptor = declaration.child_by_field_name("type")
+    return (
+        declaration.start_byte == 0
+        and declaration.end_byte == len(probe)
+        and name is not None
+        and probe[name.start_byte:name.end_byte] == b"__probhub_type"
+        and descriptor is not None
+        and len(prefix) <= descriptor.start_byte
+        and descriptor.start_byte < descriptor.end_byte
+        and descriptor.end_byte <= len(prefix) + len(type_id)
+    )
+
+
+def _recover_typeid_type_errors(parser, tree, source_bytes):
+    spans = set()
+    for issue in _syntax_issues(tree.root_node):
+        span = _enclosing_typeid_argument(issue, source_bytes)
+        if span is None or not _valid_type_id(parser, source_bytes[span[0]:span[1]]):
+            return None
+        spans.add(span)
+    if not spans:
+        return None
+
+    # Preserve every byte offset and line break while replacing only the
+    # verified type-id with an expression the grammar accepts.
+    repaired = bytearray(source_bytes)
+    for start, end in sorted(spans):
+        marker_written = False
+        for index in range(start, end):
+            if repaired[index] in {10, 13}:
+                continue
+            repaired[index] = ord("0") if not marker_written else ord(" ")
+            marker_written = True
+        if not marker_written:
+            return None
+    recovered = _parse_tree(parser, bytes(repaired))
+    return recovered if not recovered.root_node.has_error else None
+
+
+def _parse_cpp(source_bytes):
+    parser = _new_cpp_parser()
+    tree = _parse_tree(parser, source_bytes)
+    if not tree.root_node.has_error:
+        return tree
+    recovered = _recover_typeid_type_errors(parser, tree, source_bytes)
+    if recovered is None:
+        _raise_syntax_error(tree.root_node)
+    return recovered
 
 
 def _iter_nodes(root):
diff --git a/references/mutation-testing.md b/references/mutation-testing.md
index 9b88523..4d24110 100644
--- a/references/mutation-testing.md
+++ b/references/mutation-testing.md
@@ -12,7 +12,9 @@
 | `boolean-negation` | 删除 `!` 或取反 `if`/`while` 条件 | 检查布尔分支覆盖 |
 | `integer-boundary` | 只对十进制比较边界的常量尝试 `+1`/`-1` | 检查常量边界附近数据 |
 
-源码使用固定的 `tree-sitter==0.26.0` 与 `tree-sitter-cpp==0.23.4` 构造 C++ 语法树，只定位函数或 lambda 复合语句体内的真实表达式。模板尖括号、运算符声明、`<=>`、预处理宏、concept/requires、`case` 标签、`static_assert`、`sizeof` / `decltype` / `noexcept` 等非执行或未求值上下文不会生成候选；注释、字符串和字符字面量也不进入语法候选。native binding 只在独立 worker 中加载；父进程通过版本化 JSON 协议核对解析器版本、源码哈希、位置与数量。worker 默认受 30 秒、512 MiB、4 MiB stdout/stderr 共享预算和 8 个进程限制，并响应 mutation 总 deadline 与取消请求。解析超时、资源超限、native 崩溃、畸形响应或可报告的语法失败都会结构化终止、清理完整进程树，不回退到 Token 猜测，也不覆盖上一份成功 evidence。当前 `tree-sitter-cpp` 对 `typeid(type)` 等少数合法语法的支持不完整，此时命令保守失败而不猜测位置。
+源码使用固定的 `tree-sitter==0.26.0` 与 `tree-sitter-cpp==0.23.4` 构造 C++ 语法树，只定位函数或 lambda 复合语句体内的真实表达式。模板尖括号、运算符声明、`<=>`、预处理宏、concept/requires、`case` 标签、`static_assert`、`sizeof` / `decltype` / `noexcept` / `typeid` 等非执行或未求值上下文不会生成候选；注释、字符串和字符字面量也不进入语法候选。native binding 只在独立 worker 中加载；父进程通过版本化 JSON 协议核对解析器版本、源码哈希、位置与数量。worker 默认受 30 秒、512 MiB、4 MiB stdout/stderr 共享预算和 8 个进程限制，并响应 mutation 总 deadline 与取消请求。解析超时、资源超限、native 崩溃、畸形响应或可报告的语法失败都会结构化终止、清理完整进程树，不回退到 Token 猜测，也不覆盖上一份成功 evidence。
+
+固定版本会把部分合法 `typeid(type-id)` 误解析为调用表达式。worker 只在全部语法错误都位于括号完整的 `typeid(...)` 参数内、参数内容可独立解析为单个 C++ type-id、并且等长替换该参数后的完整源码无其他语法错误时恢复定位；基础类型、限定类型、指针、数组、函数指针、elaborated type 与 `decltype(...)` 均覆盖定向测试。恢复只用于确认外围语法，整个 `typeid(...)` 仍是阻断上下文；缺括号、参数内语句注入、非法 type-id 或任何邻接错误继续以 `mutation_syntax_invalid` 失败闭锁。
 
 每个变异继续使用稳定的 `cpp-token-v1` ID，计划由源码、`tree-sitter-cpp-v1` locator、算子列表、人工排除记录和上限共同决定。仍然有效的旧 ID 保持不变；旧 Token 扫描器产生但语法树不再接受的误报 ID 会成为 `unmatched`，需要作者复核后移除。解析器切换会使旧 evidence 显示 `stale`，不会把旧执行分类与新候选计划混用。
 
diff --git a/tests/test_mutation_syntax.py b/tests/test_mutation_syntax.py
index 290da95..f5aeab5 100644
--- a/tests/test_mutation_syntax.py
+++ b/tests/test_mutation_syntax.py
@@ -354,13 +354,72 @@ def test_invalid_syntax_fails_closed_without_token_fallback(self):
         self.assertEqual(raised.exception.code, "mutation_syntax_invalid")
         self.assertIn("line", str(raised.exception))
 
-    def test_unsupported_typeid_type_form_fails_closed(self):
-        with self.assertRaises(ProbHubError) as raised:
-            plan_mutations(
-                "#include <typeinfo>\n"
-                "int f(int x) { return typeid(x < 3) == typeid(bool); }\n"
-            )
-        self.assertEqual(raised.exception.code, "mutation_syntax_invalid")
+    def test_typeid_type_forms_are_recovered_without_mutating_unevaluated_content(self):
+        type_ids = (
+            "bool",
+            "const bool",
+            "bool*",
+            "bool[3]",
+            "unsigned long long",
+            "struct S",
+            "struct 类型",
+            "decltype(x < 3)",
+            "void(*)(int)",
+        )
+        for type_id in type_ids:
+            with self.subTest(type_id=type_id):
+                source = (
+                    "#include <typeinfo>\n"
+                    "struct S {};\n"
+                    "int f(int x) {\n"
+                    f"  (void)typeid({type_id});\n"
+                    "  return x < 4;\n"
+                    "}\n"
+                )
+                records = mutation_records(plan_mutations(source))
+                self.assertEqual(
+                    [(item["line"], item["column"], item["operator"], item["original"]) for item in records],
+                    [
+                        (5, 12, "comparison-boundary", "<"),
+                        (5, 14, "integer-boundary", "4"),
+                        (5, 14, "integer-boundary", "4"),
+                    ],
+                )
+
+    def test_typeid_type_recovery_preserves_existing_runtime_mutation_ids(self):
+        expression_source = (
+            "#include <typeinfo>\n"
+            "int f(int x) {\n"
+            "  (void)typeid(x);\n"
+            "  return x <= 3;\n"
+            "}\n"
+        )
+        type_source = expression_source.replace("typeid(x)", "typeid(int)")
+        expression_ids = [item.id for item in plan_mutations(expression_source)["mutations"]]
+        type_ids = [item.id for item in plan_mutations(type_source)["mutations"]]
+        self.assertEqual(type_ids, expression_ids)
+
+    def test_typeid_type_recovery_keeps_only_the_outer_runtime_comparison(self):
+        records = mutation_records(plan_mutations(
+            "#include <typeinfo>\n"
+            "int f(int x) { return typeid(x < 3) == typeid(bool); }\n"
+        ))
+        self.assertEqual(
+            [(item["line"], item["column"], item["operator"], item["original"]) for item in records],
+            [(2, 37, "comparison-boundary", "==")],
+        )
+
+    def test_typeid_type_recovery_rejects_malformed_or_unrelated_errors(self):
+        sources = (
+            "int f(int x) { (void)typeid(bool +); return x < 4; }\n",
+            "int f(int x) { (void)typeid(bool; int y); return x < 4; }\n",
+            "int f(int x) { (void)typeid(bool); return x < ; }\n",
+            "int f(int x) { (void)typeid(bool; return x < 4; }\n",
+        )
+        for source in sources:
+            with self.subTest(source=source), self.assertRaises(ProbHubError) as raised:
+                plan_mutations(source)
+            self.assertEqual(raised.exception.code, "mutation_syntax_invalid")
 
     def test_missing_or_mismatched_parser_is_structured(self):
         with patch(