diff --git a/mingw-w64-crt/stdio/fseeko64.c b/mingw-w64-crt/stdio/fseeko64.c
index 99a54f7..3161634 100644
--- a/mingw-w64-crt/stdio/fseeko64.c
+++ b/mingw-w64-crt/stdio/fseeko64.c
@@ -6,77 +6,6 @@
 #include <stdio.h>
 #include <io.h>
 #include <errno.h>
-#include <windows.h>
-#include <internal.h>
-
-struct oserr_map {
-  unsigned long oscode; /* OS values */
-  int errnocode; /* System V codes */
-};
-
-typedef union doubleint {
-  __int64 bigint;
-  struct {
-    unsigned long lowerhalf;
-    long upperhalf;
-  } twoints;
-} DINT;
-
-#define _IOYOURBUF      0x0100
-#define _IOSETVBUF      0x0400
-#define _IOFEOF         0x0800
-#define _IOFLRTN        0x1000
-#define _IOCTRLZ        0x2000
-#define _IOCOMMIT       0x4000
-
-/* General use macros */
-
-#define inuse(s)        ((s)->_flag & (_IOREAD|_IOWRT|_IORW))
-#define mbuf(s)         ((s)->_flag & _IOMYBUF)
-#define nbuf(s)         ((s)->_flag & _IONBF)
-#define ybuf(s)         ((s)->_flag & _IOYOURBUF)
-#define bigbuf(s)       ((s)->_flag & (_IOMYBUF|_IOYOURBUF))
-#define anybuf(s)       ((s)->_flag & (_IOMYBUF|_IONBF|_IOYOURBUF))
-
-#define _INTERNAL_BUFSIZ    4096
-#define _SMALL_BUFSIZ       512
-
-#define FOPEN           0x01    /* file handle open */
-#define FEOFLAG         0x02    /* end of file has been encountered */
-#define FCRLF           0x04    /* CR-LF across read buffer (in text mode) */
-#define FPIPE           0x08    /* file handle refers to a pipe */
-#define FNOINHERIT      0x10    /* file handle opened _O_NOINHERIT */
-#define FAPPEND         0x20    /* file handle opened O_APPEND */
-#define FDEV            0x40    /* file handle refers to device */
-#define FTEXT           0x80    /* file handle is in text mode */
-
-static struct oserr_map local_errtab[] = {
-  { ERROR_INVALID_FUNCTION, EINVAL }, { ERROR_FILE_NOT_FOUND, ENOENT },
-  { ERROR_PATH_NOT_FOUND, ENOENT }, { ERROR_TOO_MANY_OPEN_FILES, EMFILE },
-  { ERROR_ACCESS_DENIED, EACCES }, { ERROR_INVALID_HANDLE, EBADF },
-  { ERROR_ARENA_TRASHED, ENOMEM }, { ERROR_NOT_ENOUGH_MEMORY, ENOMEM },
-  { ERROR_INVALID_BLOCK, ENOMEM }, { ERROR_BAD_ENVIRONMENT, E2BIG },
-  { ERROR_BAD_FORMAT, ENOEXEC }, { ERROR_INVALID_ACCESS, EINVAL },
-  { ERROR_INVALID_DATA, EINVAL }, { ERROR_INVALID_DRIVE, ENOENT },
-  { ERROR_CURRENT_DIRECTORY, EACCES }, { ERROR_NOT_SAME_DEVICE, EXDEV },
-  { ERROR_NO_MORE_FILES, ENOENT }, { ERROR_LOCK_VIOLATION, EACCES },
-  { ERROR_BAD_NETPATH, ENOENT }, { ERROR_NETWORK_ACCESS_DENIED, EACCES },
-  { ERROR_BAD_NET_NAME, ENOENT }, { ERROR_FILE_EXISTS, EEXIST },
-  { ERROR_CANNOT_MAKE, EACCES }, { ERROR_FAIL_I24, EACCES },
-  { ERROR_INVALID_PARAMETER, EINVAL }, { ERROR_NO_PROC_SLOTS, EAGAIN },
-  { ERROR_DRIVE_LOCKED, EACCES }, { ERROR_BROKEN_PIPE, EPIPE },
-  { ERROR_DISK_FULL, ENOSPC }, { ERROR_INVALID_TARGET_HANDLE, EBADF },
-  { ERROR_INVALID_HANDLE, EINVAL }, { ERROR_WAIT_NO_CHILDREN, ECHILD },
-  { ERROR_CHILD_NOT_COMPLETE, ECHILD }, { ERROR_DIRECT_ACCESS_HANDLE, EBADF },
-  { ERROR_NEGATIVE_SEEK, EINVAL }, { ERROR_SEEK_ON_DEVICE, EACCES },
-  { ERROR_DIR_NOT_EMPTY, ENOTEMPTY }, { ERROR_NOT_LOCKED, EACCES },
-  { ERROR_BAD_PATHNAME, ENOENT }, { ERROR_MAX_THRDS_REACHED, EAGAIN },
-  { ERROR_LOCK_FAILED, EACCES }, { ERROR_ALREADY_EXISTS, EEXIST },
-  { ERROR_FILENAME_EXCED_RANGE, ENOENT }, { ERROR_NESTING_NOT_ALLOWED, EAGAIN },
-  { ERROR_NOT_ENOUGH_QUOTA, ENOMEM }, { 0, -1 }
-};
-
-void mingw_dosmaperr (unsigned long oserrno);
 
 int fseeko64 (FILE* stream, _off64_t offset, int whence)
 {
@@ -103,25 +32,3 @@
     }
   return fsetpos (stream, &pos);
 }
-
-void mingw_dosmaperr (unsigned long oserrno)
-{
-  size_t i;
-
-  _doserrno = oserrno;        /* set _doserrno */
-  /* check the table for the OS error code */
-  i = 0;
-  do {
-    if (oserrno == local_errtab[i].oscode)
-    {
-      errno = local_errtab[i].errnocode;
-      return;
-    }
-  } while (local_errtab[++i].errnocode != -1);
-  if (oserrno >= ERROR_WRITE_PROTECT && oserrno <= ERROR_SHARING_BUFFER_EXCEEDED)
-    errno = EACCES;
-  else if (oserrno >= ERROR_INVALID_STARTING_CODESEG && oserrno <= ERROR_INFLOOP_IN_RELOC_CHAIN)
-    errno = ENOEXEC;
-  else
-    errno = EINVAL;
-}