diff --git a/onnxscript/type_annotation.py b/onnxscript/type_annotation.py
index fb7b8a370d..345a10309f 100644
--- a/onnxscript/type_annotation.py
+++ b/onnxscript/type_annotation.py
@@ -82,15 +82,6 @@ def onnx_attr_type_to_onnxscript_repr(attr_type: onnx.AttributeProto.AttributeTy
 )
 
 
-def _remove_annotation(typeinfo: TypeAnnotationValue) -> TypeAnnotationValue:
-    """Remove Annotated wrapper if present, otherwise return typeinfo as is."""
-    if hasattr(typing, "Annotated"):
-        # Present in Python 3.9+
-        if typing.get_origin(typeinfo) is typing.Annotated:
-            return typing.get_args(typeinfo)[0]
-    return typeinfo
-
-
 def _is_primitive_attr_type(typeinfo: TypeAnnotationValue) -> bool:
     return typeinfo in _PYTYPE_TO_ATTRTYPE_MAP
 
@@ -98,7 +89,6 @@ def _is_primitive_attr_type(typeinfo: TypeAnnotationValue) -> bool:
 def pytype_to_attrtype(
     pytype: TypeAnnotationValue,
 ) -> Optional[onnx.AttributeProto.AttributeType]:
-    pytype = _remove_annotation(pytype)
     if pytype in _PYTYPE_TO_ATTRTYPE_MAP:
         return _PYTYPE_TO_ATTRTYPE_MAP[pytype]
     type_constructor = typing.get_origin(pytype)
@@ -117,7 +107,6 @@ def pytype_to_attrtype(
 
 def base_type_is_bool(pytype: TypeAnnotationValue) -> bool:
     """Returns True if base type of pytype is bool, False otherwise."""
-    pytype = _remove_annotation(pytype)
     if pytype in _PYTYPE_TO_ATTRTYPE_MAP:
         return pytype is bool
     type_constructor = typing.get_origin(pytype)
diff --git a/opgen/onnx_opset_builder.py b/opgen/onnx_opset_builder.py
index f5c3c0daab..d898376231 100644
--- a/opgen/onnx_opset_builder.py
+++ b/opgen/onnx_opset_builder.py
@@ -5,7 +5,7 @@
 
 from pathlib import Path
 from textwrap import dedent
-from typing import Annotated, Any, Iterable, Optional, Set, TextIO
+from typing import  Any, Iterable, Optional, Set, TextIO
 
 import onnx
 import pygen as cg
@@ -32,7 +32,7 @@
 MODULE_ONNX_SCRIPT_VALUES = "onnxscript.values"
 
 
-OpsetId = tuple[Annotated[str, "domain"], Annotated[int, "version"]]
+OpsetId = tuple[str, int]
 
 
 def parse_opsetid(opsetid: str) -> OpsetId: