diff --git a/Include/cpython/fileutils.h b/Include/cpython/fileutils.h
new file mode 100644
index 0000000..e79d03e
--- /dev/null
+++ b/Include/cpython/fileutils.h
@@ -0,0 +1,165 @@
+#ifndef Py_CPYTHON_FILEUTILS_H
+#  error "this header file must not be included directly"
+#endif
+
+typedef enum {
+    _Py_ERROR_UNKNOWN=0,
+    _Py_ERROR_STRICT,
+    _Py_ERROR_SURROGATEESCAPE,
+    _Py_ERROR_REPLACE,
+    _Py_ERROR_IGNORE,
+    _Py_ERROR_BACKSLASHREPLACE,
+    _Py_ERROR_SURROGATEPASS,
+    _Py_ERROR_XMLCHARREFREPLACE,
+    _Py_ERROR_OTHER
+} _Py_error_handler;
+
+PyAPI_FUNC(_Py_error_handler) _Py_GetErrorHandler(const char *errors);
+
+PyAPI_FUNC(int) _Py_DecodeLocaleEx(
+    const char *arg,
+    wchar_t **wstr,
+    size_t *wlen,
+    const char **reason,
+    int current_locale,
+    _Py_error_handler errors);
+
+PyAPI_FUNC(int) _Py_EncodeLocaleEx(
+    const wchar_t *text,
+    char **str,
+    size_t *error_pos,
+    const char **reason,
+    int current_locale,
+    _Py_error_handler errors);
+
+
+PyAPI_FUNC(PyObject *) _Py_device_encoding(int);
+
+#if defined(MS_WINDOWS) || defined(__APPLE__)
+    /* On Windows, the count parameter of read() is an int (bpo-9015, bpo-9611).
+       On macOS 10.13, read() and write() with more than INT_MAX bytes
+       fail with EINVAL (bpo-24658). */
+#   define _PY_READ_MAX  INT_MAX
+#   define _PY_WRITE_MAX INT_MAX
+#else
+    /* write() should truncate the input to PY_SSIZE_T_MAX bytes,
+       but it's safer to do it ourself to have a portable behaviour */
+#   define _PY_READ_MAX  PY_SSIZE_T_MAX
+#   define _PY_WRITE_MAX PY_SSIZE_T_MAX
+#endif
+
+#ifdef MS_WINDOWS
+struct _Py_stat_struct {
+    unsigned long st_dev;
+    uint64_t st_ino;
+    unsigned short st_mode;
+    int st_nlink;
+    int st_uid;
+    int st_gid;
+    unsigned long st_rdev;
+    __int64 st_size;
+    time_t st_atime;
+    int st_atime_nsec;
+    time_t st_mtime;
+    int st_mtime_nsec;
+    time_t st_ctime;
+    int st_ctime_nsec;
+    unsigned long st_file_attributes;
+    unsigned long st_reparse_tag;
+};
+#else
+#  define _Py_stat_struct stat
+#endif
+
+PyAPI_FUNC(int) _Py_fstat(
+    int fd,
+    struct _Py_stat_struct *status);
+
+PyAPI_FUNC(int) _Py_fstat_noraise(
+    int fd,
+    struct _Py_stat_struct *status);
+
+PyAPI_FUNC(int) _Py_stat(
+    PyObject *path,
+    struct stat *status);
+
+PyAPI_FUNC(int) _Py_open(
+    const char *pathname,
+    int flags);
+
+PyAPI_FUNC(int) _Py_open_noraise(
+    const char *pathname,
+    int flags);
+
+PyAPI_FUNC(FILE *) _Py_wfopen(
+    const wchar_t *path,
+    const wchar_t *mode);
+
+PyAPI_FUNC(FILE*) _Py_fopen(
+    const char *pathname,
+    const char *mode);
+
+PyAPI_FUNC(FILE*) _Py_fopen_obj(
+    PyObject *path,
+    const char *mode);
+
+PyAPI_FUNC(Py_ssize_t) _Py_read(
+    int fd,
+    void *buf,
+    size_t count);
+
+PyAPI_FUNC(Py_ssize_t) _Py_write(
+    int fd,
+    const void *buf,
+    size_t count);
+
+PyAPI_FUNC(Py_ssize_t) _Py_write_noraise(
+    int fd,
+    const void *buf,
+    size_t count);
+
+#ifdef HAVE_READLINK
+PyAPI_FUNC(int) _Py_wreadlink(
+    const wchar_t *path,
+    wchar_t *buf,
+    /* Number of characters of 'buf' buffer
+       including the trailing NUL character */
+    size_t buflen);
+#endif
+
+#ifdef HAVE_REALPATH
+PyAPI_FUNC(wchar_t*) _Py_wrealpath(
+    const wchar_t *path,
+    wchar_t *resolved_path,
+    /* Number of characters of 'resolved_path' buffer
+       including the trailing NUL character */
+    size_t resolved_path_len);
+#endif
+
+#ifndef MS_WINDOWS
+PyAPI_FUNC(int) _Py_isabs(const wchar_t *path);
+#endif
+
+PyAPI_FUNC(int) _Py_abspath(const wchar_t *path, wchar_t **abspath_p);
+
+PyAPI_FUNC(wchar_t*) _Py_wgetcwd(
+    wchar_t *buf,
+    /* Number of characters of 'buf' buffer
+       including the trailing NUL character */
+    size_t buflen);
+
+PyAPI_FUNC(int) _Py_get_inheritable(int fd);
+
+PyAPI_FUNC(int) _Py_set_inheritable(int fd, int inheritable,
+                                    int *atomic_flag_works);
+
+PyAPI_FUNC(int) _Py_set_inheritable_async_safe(int fd, int inheritable,
+                                               int *atomic_flag_works);
+
+PyAPI_FUNC(int) _Py_dup(int fd);
+
+#ifndef MS_WINDOWS
+PyAPI_FUNC(int) _Py_get_blocking(int fd);
+
+PyAPI_FUNC(int) _Py_set_blocking(int fd, int blocking);
+#endif   /* !MS_WINDOWS */