diff --git a/Include/Python.h b/Include/Python.h
index bf1ca6c..1bac5bd 100644
--- a/Include/Python.h
+++ b/Include/Python.h
@@ -32,7 +32,7 @@
 #include <errno.h>
 #endif
 #include <stdlib.h>
-#ifdef HAVE_UNISTD_H
+#ifndef MS_WINDOWS
 #include <unistd.h>
 #endif
 #ifdef HAVE_CRYPT_H
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 7c02351..2fddd95 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -213,41 +213,6 @@
 extern char        *ctermid_r(char *);
 #endif
 
-#ifndef HAVE_UNISTD_H
-#if ( defined(__WATCOMC__) || defined(_MSC_VER) ) && !defined(__QNX__)
-extern int mkdir(const char *);
-#else
-extern int mkdir(const char *, mode_t);
-#endif
-#if defined(__IBMC__) || defined(__IBMCPP__)
-extern int chdir(char *);
-extern int rmdir(char *);
-#else
-extern int chdir(const char *);
-extern int rmdir(const char *);
-#endif
-extern int chmod(const char *, mode_t);
-/*#ifdef HAVE_FCHMOD
-extern int fchmod(int, mode_t);
-#endif*/
-/*#ifdef HAVE_LCHMOD
-extern int lchmod(const char *, mode_t);
-#endif*/
-extern int chown(const char *, uid_t, gid_t);
-extern char *getcwd(char *, int);
-extern char *strerror(int);
-extern int link(const char *, const char *);
-extern int rename(const char *, const char *);
-extern int stat(const char *, struct stat *);
-extern int unlink(const char *);
-#ifdef HAVE_SYMLINK
-extern int symlink(const char *, const char *);
-#endif /* HAVE_SYMLINK */
-#ifdef HAVE_LSTAT
-extern int lstat(const char *, struct stat *);
-#endif /* HAVE_LSTAT */
-#endif /* !HAVE_UNISTD_H */
-
 #endif /* !_MSC_VER */
 
 #ifdef HAVE_POSIX_SPAWN
diff --git a/Modules/resource.c b/Modules/resource.c
index e59280f..87c72e7 100644
--- a/Modules/resource.c
+++ b/Modules/resource.c
@@ -4,10 +4,7 @@
 #include <sys/time.h>
 #include <string.h>
 #include <errno.h>
-/* for sysconf */
-#if defined(HAVE_UNISTD_H)
 #include <unistd.h>
-#endif
 
 /* On some systems, these aren't in any header file.
    On others they are, with inconsistent prototypes.
diff --git a/configure b/configure
index ddfd1c4..22fc021 100755
--- a/configure
+++ b/configure
@@ -7725,7 +7725,7 @@
 fcntl.h grp.h \
 ieeefp.h io.h langinfo.h libintl.h process.h pthread.h \
 sched.h shadow.h signal.h stropts.h termios.h \
-unistd.h utime.h \
+utime.h \
 poll.h sys/devpoll.h sys/epoll.h sys/poll.h \
 sys/audioio.h sys/xattr.h sys/bsdtty.h sys/event.h sys/file.h sys/ioctl.h \
 sys/kern_control.h sys/loadavg.h sys/lock.h sys/mkdev.h sys/modem.h \
diff --git a/configure.ac b/configure.ac
index cc1bba4..0395362 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2066,7 +2066,7 @@
 fcntl.h grp.h \
 ieeefp.h io.h langinfo.h libintl.h process.h pthread.h \
 sched.h shadow.h signal.h stropts.h termios.h \
-unistd.h utime.h \
+utime.h \
 poll.h sys/devpoll.h sys/epoll.h sys/poll.h \
 sys/audioio.h sys/xattr.h sys/bsdtty.h sys/event.h sys/file.h sys/ioctl.h \
 sys/kern_control.h sys/loadavg.h sys/lock.h sys/mkdev.h sys/modem.h \