diff --git a/imperative/python/megengine/traced_module/utils.py b/imperative/python/megengine/traced_module/utils.py
index 197c602ef3860bcdd689bc9a8d735115607c3eed..f9c3c46e59a0144bd5678be96e10ce0c4e0ce2e7 100644
--- a/imperative/python/megengine/traced_module/utils.py
+++ b/imperative/python/megengine/traced_module/utils.py
@@ -147,13 +147,14 @@ class _ModuleDict(Module, MutableMapping):
 
     def __init__(self, modules: Optional[Dict[str, Module]] = None):
         super().__init__()
-        self._size = 0
+        self._module_keys = []
         if modules is not None:
             self.update(modules)
 
     def __delitem__(self, key):
         delattr(self, key)
-        self._size -= 1
+        assert key in self._module_keys
+        self._module_keys.remove(key)
 
     def __getitem__(self, key):
         return getattr(self, key)
@@ -162,22 +163,23 @@ class _ModuleDict(Module, MutableMapping):
         if not isinstance(value, Module):
             raise ValueError("invalid sub-module")
         setattr(self, key, value)
-        self._size += 1
+        if key not in self._module_keys:
+            self._module_keys.append(key)
 
     def __iter__(self):
         return iter(self.keys())
 
     def __len__(self):
-        return self._size
+        return len(self._module_keys)
 
     def items(self):
-        return dict(self.named_children()).items()
+        return [(key, getattr(self, key)) for key in self._module_keys]
 
     def values(self):
-        return dict(self.named_children()).values()
+        return [getattr(self, key) for key in self._module_keys]
 
     def keys(self):
-        return dict(self.named_children()).keys()
+        return self._module_keys
 
     def forward(self):
         raise RuntimeError("ModuleList is not callable")
diff --git a/imperative/python/test/unit/traced_module/test_trace_module.py b/imperative/python/test/unit/traced_module/test_trace_module.py
index 49432d66c7c3a9963205a0b44e68a5d467b92d7d..d18d08351240d7995e7b0dc512dee9f563b8b227 100644
--- a/imperative/python/test/unit/traced_module/test_trace_module.py
+++ b/imperative/python/test/unit/traced_module/test_trace_module.py
@@ -1,3 +1,5 @@
+from collections import OrderedDict
+
 import numpy as np
 
 import megengine.functional as F
@@ -29,14 +31,19 @@ class MyModule3(M.Module):
         self.modules = [
             M.Elemwise("ADD"),
             M.Elemwise("ADD"),
-            {"a": M.Elemwise("ADD"), "b": M.Elemwise("ADD")},
+            OrderedDict([("a", M.Elemwise("ADD")), ("b", M.Elemwise("ADD"))]),
+            M.Elemwise("RELU"),
+            M.Elemwise("RELU"),
         ]
 
     def forward(self, a, b):
         x = self.modules[0](a, b)
         y = self.modules[1](a, b)
-        y = self.modules[2]["a"](x, y)
-        y = self.modules[2]["b"](x, y)
+        assert list(self.modules[2].keys()) == ["a", "b"]
+        for _, m in self.modules[2].items():
+            y = m(x, y)
+        for m in self.modules[3:]:
+            y = m(y)
         return y
 
 
@@ -78,6 +85,7 @@ def test_trace_module():
     assert isinstance(tm3.modules.__dict__["0"], M.Elemwise)
     assert isinstance(tm3.modules.__dict__["2"], TracedModule)
     assert isinstance(tm3.modules.__dict__["2"].a, M.Elemwise)
+    assert isinstance(tm3.modules.__dict__["3"], M.Elemwise)
 
     m4 = MyModule4()
     tm4 = trace_module(m4, a, b)