diff --git a/stdlib/3/_osx_support.pyi b/stdlib/3/_osx_support.pyi
new file mode 100644
index 000000000..6dc0e93e7
--- /dev/null
+++ b/stdlib/3/_osx_support.pyi
@@ -0,0 +1,33 @@
+
+from typing import Tuple, List, Optional, Dict, Sequence, Iterable, TypeVar, Union
+
+_T = TypeVar('_T')
+_K = TypeVar('_K')
+_V = TypeVar('_V')
+
+__all__: List[str]
+
+_UNIVERSAL_CONFIG_VARS: Tuple[str, ...]  # undocumented
+_COMPILER_CONFIG_VARS: Tuple[str, ...]  # undocumented
+_INITPRE: str  # undocumented
+
+def _find_executable(executable: str, path: Optional[str] = ...) -> Optional[str]: ...  # undocumented
+def _read_output(commandstring: str) -> Optional[str]: ...  # undocumented
+def _find_build_tool(toolname: str) -> str: ...  # undocumented
+
+_SYSTEM_VERSION: Optional[str]  # undocumented
+
+def _get_system_version() -> str: ...  # undocumented
+def _remove_original_values(_config_vars: Dict[str, str]) -> None: ...  # undocumented
+def _save_modified_value(_config_vars: Dict[str, str], cv: str, newvalue: str) -> None: ...  # undocumented
+def _supports_universal_builds() -> bool: ...  # undocumented
+def _find_appropriate_compiler(_config_vars: Dict[str, str]) -> Dict[str, str]: ...  # undocumented
+def _remove_universal_flags(_config_vars: Dict[str, str]) -> Dict[str, str]: ...  # undocumented
+def _remove_unsupported_archs(_config_vars: Dict[str, str]) -> Dict[str, str]: ...  # undocumented
+def _override_all_archs(_config_vars: Dict[str, str]) -> Dict[str, str]: ...  # undocumented
+def _check_for_unavailable_sdk(_config_vars: Dict[str, str]) -> Dict[str, str]: ...  # undocumented
+
+def compiler_fixup(compiler_so: Iterable[str], cc_args: Sequence[str]) -> List[str]: ...
+def customize_config_vars(_config_vars: Dict[str, str]) -> Dict[str, str]: ...
+def customize_compiler(_config_vars: Dict[str, str]) -> Dict[str, str]: ...
+def get_platform_osx(_config_vars: Dict[str, str], osname: _T, release: _K, machine: _V) -> Tuple[Union[str, _T], Union[str, _K], Union[str, _V]]: ...