diff --git a/pybind11/_version.pyi b/pybind11/_version.pyi
new file mode 100644
index 0000000000..d45e5dc907
--- /dev/null
+++ b/pybind11/_version.pyi
@@ -0,0 +1,6 @@
+from typing import Tuple, Union
+
+def _to_int(s: str) -> Union[int, str]: ...
+
+__version__: str
+version_info: Tuple[Union[int, str], ...]
diff --git a/pybind11/setup_helpers.pyi b/pybind11/setup_helpers.pyi
new file mode 100644
index 0000000000..074744eb82
--- /dev/null
+++ b/pybind11/setup_helpers.pyi
@@ -0,0 +1,63 @@
+# IMPORTANT: Should stay in sync with setup_helpers.py (mostly checked by CI /
+# pre-commit).
+
+import contextlib
+import distutils.ccompiler
+from distutils.command.build_ext import build_ext as _build_ext  # type: ignore
+from distutils.extension import Extension as _Extension
+from types import TracebackType
+from typing import Any, Callable, Dict, Iterator, List, Optional, Type, TypeVar, Union
+
+WIN: bool
+PY2: bool
+MACOS: bool
+STD_TMPL: str
+
+class Pybind11Extension(_Extension):
+    def _add_cflags(self, *flags: str) -> None: ...
+    def _add_lflags(self, *flags: str) -> None: ...
+    def __init__(
+        self, *args: Any, cxx_std: int = 0, language: str = "c++", **kwargs: Any
+    ) -> None: ...
+    @property
+    def cxx_std(self) -> int: ...
+    @cxx_std.setter
+    def cxx_std(self, level: int) -> None: ...
+
+@contextlib.contextmanager
+def tmp_chdir() -> Iterator[str]: ...
+def has_flag(compiler: distutils.ccompiler.CCompiler, flag: str) -> bool: ...
+def auto_cpp_level(compiler: distutils.ccompiler.CCompiler) -> Union[int, str]: ...
+
+class build_ext(_build_ext):  # type: ignore
+    def build_extensions(self) -> None: ...
+
+def intree_extensions(
+    paths: Iterator[str], package_dir: Optional[Dict[str, str]] = None
+) -> List[Pybind11Extension]: ...
+def no_recompile(obj: str, src: str) -> bool: ...
+def naive_recompile(obj: str, src: str) -> bool: ...
+
+T = TypeVar("T", bound="ParallelCompile")
+
+class ParallelCompile:
+    envvar: Optional[str]
+    default: int
+    max: int
+    needs_recompile: Callable[[str, str], bool]
+    def __init__(
+        self,
+        envvar: Optional[str] = None,
+        default: int = 0,
+        max: int = 0,
+        needs_recompile: Callable[[str, str], bool] = no_recompile,
+    ) -> None: ...
+    def function(self) -> Any: ...
+    def install(self: T) -> T: ...
+    def __enter__(self: T) -> T: ...
+    def __exit__(
+        self,
+        exc_type: Optional[Type[BaseException]],
+        exc_value: Optional[BaseException],
+        traceback: Optional[TracebackType],
+    ) -> None: ...