diff --git a/mashumaro/core/meta/code/builder.py b/mashumaro/core/meta/code/builder.py
index 1ef9f938..655cde76 100644
--- a/mashumaro/core/meta/code/builder.py
+++ b/mashumaro/core/meta/code/builder.py
@@ -45,6 +45,7 @@
     is_hashable,
     is_init_var,
     is_literal,
+    is_local_type,
     is_named_tuple,
     is_optional,
     is_type_var_any,
@@ -52,7 +53,7 @@
     substitute_type_params,
     type_name,
 )
-from mashumaro.core.meta.types.common import FieldContext, NoneType, ValueSpec
+from mashumaro.core.meta.types.common import FieldContext, NoneType, ValueSpec, clean_id
 from mashumaro.core.meta.types.pack import PackerRegistry
 from mashumaro.core.meta.types.unpack import (
     SubtypeUnpackerBuilder,
@@ -80,8 +81,6 @@
 __POST_SERIALIZE__ = "__post_serialize__"
 __POST_DESERIALIZE__ = "__post_deserialize__"
 
-_LOCALS_TYPE_VAR = "__locals_type_var__"
-
 
 class InternalMethodName(str):
     _PREFIX = "__mashumaro_"
@@ -306,8 +305,7 @@ def compile(self) -> None:
                 print(f"{type_name(self.cls)}:")
             print(code)
 
-        localns = {**self.__dict__, _LOCALS_TYPE_VAR: self.cls}
-        exec(code, self.globals, localns)
+        exec(code, self.globals, self.__dict__)
 
     def evaluate_forward_ref(
         self,
@@ -560,8 +558,9 @@ def _unpack_method_set_value(
             resolved_type_params=self.get_field_resolved_type_params(fname),
         )
 
-        if "<locals>" in field_type:
-            field_type = _LOCALS_TYPE_VAR
+        if is_local_type(ftype):
+            field_type = clean_id(field_type)
+            self.ensure_object_imported(ftype, field_type)
 
         could_be_none = (
             ftype in (typing.Any, type(None), None)
diff --git a/mashumaro/core/meta/helpers.py b/mashumaro/core/meta/helpers.py
index 2d27c44d..e556c3aa 100644
--- a/mashumaro/core/meta/helpers.py
+++ b/mashumaro/core/meta/helpers.py
@@ -387,6 +387,8 @@ def is_literal(typ: Type) -> bool:
             return type(typ) is typing._LiteralGenericAlias  # type: ignore
     return False
 
+def is_local_type(typ: Type) -> bool:
+    return "<locals>" in getattr(typ, "__qualname__", "")
 
 def not_none_type_arg(
     type_args: Tuple[Type, ...],
diff --git a/mashumaro/core/meta/types/common.py b/mashumaro/core/meta/types/common.py
index c5a1e282..bf6626d2 100644
--- a/mashumaro/core/meta/types/common.py
+++ b/mashumaro/core/meta/types/common.py
@@ -1,4 +1,5 @@
 import collections.abc
+import re
 import uuid
 from abc import ABC, abstractmethod
 from dataclasses import dataclass, field, replace
@@ -302,8 +303,10 @@ def expr_or_maybe_none(spec: ValueSpec, new_expr: Expression) -> Expression:
 def random_hex() -> str:
     return str(uuid.uuid4().hex)
 
+_PY_VALID_ID_RE = re.compile(r"\W|^(?=\d)")
 
 def clean_id(value: str) -> str:
-    for c in ".<>":
-        value = value.replace(c, "_")
-    return value
+    if not value:
+        return "_"
+
+    return _PY_VALID_ID_RE.sub("_", value)