diff --git a/lib/core/Handles/HandlesAsyncFunctions.py b/lib/core/Handles/HandlesAsyncFunctions.py
index 949247b..b475404 100644
--- a/lib/core/Handles/HandlesAsyncFunctions.py
+++ b/lib/core/Handles/HandlesAsyncFunctions.py
@@ -146,6 +146,7 @@ class AsyncFunctionHandle(BaseHandle):
         frame_ty: ir.IdentifiedStructType = ir.IdentifiedStructType(Gen.module, f'Coro_{name}')
         frame_ty.set_body(*fields)
         Gen._coro_frame_types[name] = frame_ty
+        Gen.structs[f'Coro_{name}'] = frame_ty
         Gen._coro_local_vars[name] = local_names
         return frame_ty
 
diff --git a/lib/core/LLVMCG/StructGen.py b/lib/core/LLVMCG/StructGen.py
index f6eb280..a705710 100644
--- a/lib/core/LLVMCG/StructGen.py
+++ b/lib/core/LLVMCG/StructGen.py
@@ -168,6 +168,18 @@ class StructGenMixin:
                 else:
                     struct_defs.append(f'{sname_ir} = type {{ {elems} }}')
                 struct_names.add(sname)
+        # 协程帧结构体兜底（M1）：帧注册进 Gen.structs 时上面已输出；
+        # 未注册（被 _generate_structs 清空）时这里补齐定义，避免
+        # getelementptr base element must be sized。
+        coro_frames: dict = getattr(self, '_coro_frame_types', None) or {}
+        for _cf_name, _cf_ty in coro_frames.items():
+            if _cf_name in struct_names:
+                continue
+            if isinstance(_cf_ty, ir.IdentifiedStructType) and _cf_ty.elements:
+                _cf_sname: str = _cf_ty.name
+                _cf_ir: str = f'%"{_cf_sname}"' if (_cf_sname[0].isdigit() or "." in _cf_sname) else f'%{_cf_sname}'
+                struct_defs.append(f'{_cf_ir} = type {{ {", ".join(str(e) for e in _cf_ty.elements)} }}')
+                struct_names.add(_cf_sname)
         if struct_defs:
             lines: list[str] = ir_text.split('\n')
             # 预计算全部 "= type" 定义行前缀（一次性），用 str.startswith(tuple)