diff --git a/distutils/_dataclass.py b/distutils/_dataclass.py
index 0ce2e3c8..41eb9b3b 100644
--- a/distutils/_dataclass.py
+++ b/distutils/_dataclass.py
@@ -4,11 +4,11 @@
 import warnings
 from dataclasses import dataclass, fields
 from functools import wraps
-from typing import TypeVar
+from typing import Any, TypeVar, cast
 
 from .compat.py310 import dataclass_transform
 
-_T = TypeVar("_T", bound=type)
+_T = TypeVar("_T", bound=type[Any])
 
 
 @dataclass_transform()
@@ -26,7 +26,7 @@ def lenient_dataclass(**dc_kwargs):
     """
 
     @wraps(dataclass)
-    def _wrap(cls: _T) -> _T:  # type: ignore[var-annotated]
+    def _wrap(cls: _T) -> _T:
         cls = dataclass(**dc_kwargs)(cls)
         # Allowed field names in order
         safe = tuple(f.name for f in fields(cls))
@@ -50,6 +50,6 @@ def _wrapped_init(self, *args, **kwargs):
             return orig_init(self, **positional, **keywords)
 
         cls.__init__ = _wrapped_init
-        return cls
+        return cast("_T", cls)
 
     return _wrap
diff --git a/distutils/_modified.py b/distutils/_modified.py
index 4033c079..f45ed35b 100644
--- a/distutils/_modified.py
+++ b/distutils/_modified.py
@@ -57,7 +57,11 @@ def newer_pairwise(
     of 'newer()'.
     """
     newer_pairs = filter(splat(newer), zip(sources, targets, strict=True))
-    return tuple(map(list, zip(*newer_pairs, strict=False))) or ([], [])
+
+    return (
+        tuple(map(list, zip(*newer_pairs, strict=False)))  # type: ignore[return-value] # FIXME: pypa/distutils#411
+        or ([], [])
+    )
 
 
 def newer_group(
@@ -91,4 +95,4 @@ def missing_as_newer(source):
     )
 
 
-newer_pairwise_group = functools.partial(newer_pairwise, newer=newer_group)
+newer_pairwise_group = functools.partial(newer_pairwise, newer=newer_group)  # type: ignore[type-var] # FIXME: pypa/distutils#411
diff --git a/distutils/command/install_lib.py b/distutils/command/install_lib.py
index a9300de7..59551a8c 100644
--- a/distutils/command/install_lib.py
+++ b/distutils/command/install_lib.py
@@ -124,7 +124,7 @@ def install(self) -> list[str] | Any:
             self.warn(
                 f"'{self.build_dir}' does not exist -- no Python modules to install"
             )
-            return
+            return None
         return outfiles
 
     def byte_compile(self, files) -> None:
diff --git a/distutils/compilers/C/base.py b/distutils/compilers/C/base.py
index acb9d96b..96aa12d4 100644
--- a/distutils/compilers/C/base.py
+++ b/distutils/compilers/C/base.py
@@ -43,7 +43,6 @@
 
 _Macro: TypeAlias = tuple[str] | tuple[str, str | None]
 _StrPathT = TypeVar("_StrPathT", bound="str | os.PathLike[str]")
-_BytesPathT = TypeVar("_BytesPathT", bound="bytes | os.PathLike[bytes]")
 
 
 class Compiler:
@@ -431,7 +430,7 @@ def _fix_compile_args(
         output_dir: str | None,
         macros: list[_Macro] | None,
         include_dirs: list[str] | tuple[str, ...] | None,
-    ) -> tuple[str, list[_Macro], list[str]]:
+    ) -> tuple[str | None, list[_Macro], list[str]]:
         """Typecheck and fix-up some of the arguments to the 'compile()'
         method, and return fixed-up values.  Specifically: if 'output_dir'
         is None, replaces it with 'self.output_dir'; ensures that 'macros'
@@ -483,7 +482,7 @@ def _prep_compile(self, sources, output_dir, depends=None):
 
     def _fix_object_args(
         self, objects: list[str] | tuple[str, ...], output_dir: str | None
-    ) -> tuple[list[str], str]:
+    ) -> tuple[list[str], str | None]:
         """Typecheck and fix up some arguments supplied to various methods.
         Specifically: ensure that 'objects' is a list; if output_dir is
         None, replace with self.output_dir.  Return fixed versions of
@@ -1123,9 +1122,10 @@ def library_filename(
         libname: str,
         lib_type: str = "static",
         strip_dir: bool = False,
-        output_dir: str | os.PathLike[str] = "",  # or 'shared'
+        output_dir: str | os.PathLike[str] | None = "",  # or 'shared'
     ):
-        assert output_dir is not None
+        if output_dir is None:
+            output_dir = ""
         expected = '"static", "shared", "dylib", "xcode_stub"'
         if lib_type not in eval(expected):
             raise ValueError(f"'lib_type' must be {expected}")
@@ -1195,19 +1195,7 @@ def spawn(
         with _translate_errors(cmd):
             self.call(cmd, env=env, **kwargs)
 
-    @overload
-    def move_file(
-        self, src: str | os.PathLike[str], dst: _StrPathT
-    ) -> _StrPathT | str: ...
-    @overload
-    def move_file(
-        self, src: bytes | os.PathLike[bytes], dst: _BytesPathT
-    ) -> _BytesPathT | bytes: ...
-    def move_file(
-        self,
-        src: str | os.PathLike[str] | bytes | os.PathLike[bytes],
-        dst: str | os.PathLike[str] | bytes | os.PathLike[bytes],
-    ) -> str | os.PathLike[str] | bytes | os.PathLike[bytes]:
+    def move_file(self, src: str | os.PathLike[str], dst: _StrPathT) -> _StrPathT | str:
         return shutil.move(src, dst)
 
     def mkpath(self, name, mode=0o777):
diff --git a/mypy.ini b/mypy.ini
index 48ddecfd..07f0a277 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -19,10 +19,6 @@ disable_error_code =
 	# Code that is too dynamic using variable command names;
 	# and code that uses platform checks mypy doesn't understand
 	attr-defined,
-	# These reveal issues in distutils/_modified.py that should be fixed
-	# https://github.com/pypa/distutils/issues/411
-	return-value,
-	type-var,
 	# TODO: Resolve and re-enable these gradually
 	operator,
 	arg-type,