diff --git a/setuptools/config/expand.py b/setuptools/config/expand.py
index d9a2ded430..b581515202 100644
--- a/setuptools/config/expand.py
+++ b/setuptools/config/expand.py
@@ -32,7 +32,7 @@
 from itertools import chain
 from pathlib import Path
 from types import ModuleType, TracebackType
-from typing import TYPE_CHECKING, Any, Callable, TypeVar
+from typing import TYPE_CHECKING, Any, Callable, TypeVar, cast
 
 from .. import _static
 from .._path import StrPath, same_path as _same_path
@@ -122,7 +122,9 @@ def read_files(
     from more_itertools import always_iterable
 
     root_dir = os.path.abspath(root_dir or os.getcwd())
-    _filepaths = (os.path.join(root_dir, path) for path in always_iterable(filepaths))
+    # work around more_itertools/more_itertools#1143
+    _filepaths = cast('Iterable[StrPath]', always_iterable(filepaths))
+    _filepaths = (os.path.join(root_dir, path) for path in _filepaths)
     return '\n'.join(
         _read_file(path)
         for path in _filter_existing_files(_filepaths)