diff --git a/flowrep/models/parsers/object_scope.py b/flowrep/models/parsers/object_scope.py
index 3923cad7..ea28cb90 100644
--- a/flowrep/models/parsers/object_scope.py
+++ b/flowrep/models/parsers/object_scope.py
@@ -3,6 +3,7 @@
 import ast
 import builtins
 import inspect
+import sys
 from collections.abc import Callable
 from typing import Any
 
@@ -45,7 +46,18 @@ def fork(self) -> ScopeProxy:
 
 
 def get_scope(func: Callable[..., Any] | type[Any]) -> ScopeProxy:
-    return ScopeProxy(inspect.getmodule(func).__dict__ | vars(builtins))
+    module = inspect.getmodule(func)
+    if module is None:
+        module_name = getattr(func, "__module__", None)
+        if module_name is not None:
+            module = sys.modules.get(module_name)
+    if module is None:
+        raise ValueError(
+            f"Cannot determine the module for {func!r}. "
+            "inspect.getmodule() returned None and no resolvable __module__ "
+            "attribute was found."
+        )
+    return ScopeProxy(module.__dict__ | vars(builtins))
 
 
 def resolve_attribute_to_object(attribute: str, scope: ScopeProxy | object) -> object:
diff --git a/tests/unit/models/parsers/test_object_scope.py b/tests/unit/models/parsers/test_object_scope.py
index 7fc2bcb0..a10c0e70 100644
--- a/tests/unit/models/parsers/test_object_scope.py
+++ b/tests/unit/models/parsers/test_object_scope.py
@@ -1,4 +1,6 @@
 import ast
+import sys
+import types
 import unittest
 
 from flowrep.models.parsers import object_scope
@@ -42,6 +44,36 @@ def test_includes_builtins(self):
         self.assertIs(scope.int, int)
         self.assertIs(scope.ValueError, ValueError)
 
+    def test_none_module_fallback_via_dunder_module(self):
+        """When inspect.getmodule returns None but __module__ is set, fall back."""
+        mod = types.ModuleType("_test_dynamic_mod")
+        mod.__dict__["sentinel"] = object()
+        sys.modules["_test_dynamic_mod"] = mod
+        try:
+            func = types.FunctionType(
+                (lambda: None).__code__,
+                {},
+                "_test_func",
+            )
+            # Manually set __module__ but keep the function out of a real module
+            # so inspect.getmodule() returns None.
+            func.__module__ = "_test_dynamic_mod"
+            scope = object_scope.get_scope(func)
+            self.assertIs(scope.sentinel, mod.__dict__["sentinel"])
+        finally:
+            del sys.modules["_test_dynamic_mod"]
+
+    def test_no_resolvable_module_raises_value_error(self):
+        """When neither inspect.getmodule nor __module__ resolves, raise ValueError."""
+        func = types.FunctionType(
+            (lambda: None).__code__,
+            {},
+            "_orphan_func",
+        )
+        func.__module__ = None  # type: ignore[assignment]
+        with self.assertRaises(ValueError):
+            object_scope.get_scope(func)
+
 
 class TestResolveSymbolToObject(unittest.TestCase):
     def test_simple_name(self):