diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index f10972709..8744ac9cc 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,8 @@
+2013-11-25  Corinna Vinschen  <corinna@vinschen.de>
+
+	Throughout, keep function definitions and declarations in sync with
+	newlib in terms of C99 "restrict" keyword.
+
 2013-11-24  Corinna Vinschen  <corinna@vinschen.de>
 
 	* dtable.cc: Include sys/param.h for MAX definition.
diff --git a/winsup/cygwin/dir.cc b/winsup/cygwin/dir.cc
index fe0babc99..dc6e2a740 100644
--- a/winsup/cygwin/dir.cc
+++ b/winsup/cygwin/dir.cc
@@ -177,7 +177,7 @@ readdir (DIR *dir)
 }
 
 extern "C" int
-readdir_r (DIR *dir, dirent *de, dirent **ode)
+readdir_r (DIR *__restrict dir, dirent *__restrict de, dirent **__restrict ode)
 {
   int res = readdir_worker (dir, de);
   if (!res)
diff --git a/winsup/cygwin/glob.cc b/winsup/cygwin/glob.cc
index 296cd7fbc..be2a6013b 100644
--- a/winsup/cygwin/glob.cc
+++ b/winsup/cygwin/glob.cc
@@ -186,7 +186,7 @@ static void	 qprintf(const char *, Char *);
 #endif
 
 int
-glob(const char *pattern, int flags, int (*errfunc)(const char *, int), glob_t *pglob)
+glob(const char *__restrict pattern, int flags, int (*errfunc)(const char *, int), glob_t *__restrict pglob)
 {
 	const char *patnext;
 	size_t limit;
diff --git a/winsup/cygwin/include/cygwin/stat.h b/winsup/cygwin/include/cygwin/stat.h
index ed96fafd9..73f3e9310 100644
--- a/winsup/cygwin/include/cygwin/stat.h
+++ b/winsup/cygwin/include/cygwin/stat.h
@@ -1,6 +1,6 @@
 /* cygwin/stat.h
 
-   Copyright 2002, 2007, 2010 Red Hat Inc.
+   Copyright 2002, 2007, 2010, 2013 Red Hat Inc.
    Written by Corinna Vinschen <corinna@vinschen.de>
 
 This file is part of Cygwin.
@@ -56,8 +56,10 @@ struct __stat32
 #endif
 
 extern int fstat64 (int fd, struct stat *buf);
-extern int stat64 (const char *file_name, struct stat *buf);
-extern int lstat64 (const char *file_name, struct stat *buf);
+extern int stat64 (const char *__restrict file_name,
+		   struct stat *__restrict buf);
+extern int lstat64 (const char *__restrict file_name,
+		    struct stat *__restrict buf);
 
 #endif
 
diff --git a/winsup/cygwin/include/glob.h b/winsup/cygwin/include/glob.h
index 35745196b..4ad200fd5 100644
--- a/winsup/cygwin/include/glob.h
+++ b/winsup/cygwin/include/glob.h
@@ -103,7 +103,7 @@ __BEGIN_DECLS
 # define DLLEXPORT __declspec(dllimport)
 #endif
 
-int	DLLEXPORT glob (const char *, int, int (*)(const char *, int), glob_t *);
+int	DLLEXPORT glob (const char __restrict *, int, int (*)(const char *, int), glob_t *__restrict);
 void	DLLEXPORT globfree (glob_t *);
 int	DLLEXPORT glob_pattern_p (const char *, int);
 __END_DECLS
diff --git a/winsup/cygwin/include/sys/dirent.h b/winsup/cygwin/include/sys/dirent.h
index 027fa8f73..46c34ab5e 100644
--- a/winsup/cygwin/include/sys/dirent.h
+++ b/winsup/cygwin/include/sys/dirent.h
@@ -65,7 +65,8 @@ typedef struct __DIR
 DIR *opendir (const char *);
 DIR *fdopendir (int);
 struct dirent *readdir (DIR *);
-int readdir_r (DIR *, struct dirent *, struct dirent **);
+int readdir_r (DIR * __restrict, struct dirent * __restrict,
+	       struct dirent ** __restrict);
 void rewinddir (DIR *);
 int closedir (DIR *);
 
diff --git a/winsup/cygwin/libc/strptime.cc b/winsup/cygwin/libc/strptime.cc
index ca059842a..eeaab831c 100644
--- a/winsup/cygwin/libc/strptime.cc
+++ b/winsup/cygwin/libc/strptime.cc
@@ -763,7 +763,8 @@ literal:
 }
 
 char *
-strptime (const char *buf, const char *fmt, struct tm *tm)
+strptime (const char *__restrict buf, const char *__restrict fmt,
+	  struct tm *__restrict tm)
 {
   era_info_t *era_info = NULL;
   alt_digits_t *alt_digits = NULL;
diff --git a/winsup/cygwin/localtime.cc b/winsup/cygwin/localtime.cc
index 19eef6759..a5307101e 100644
--- a/winsup/cygwin/localtime.cc
+++ b/winsup/cygwin/localtime.cc
@@ -1749,7 +1749,7 @@ localsub(const timezone_t sp, const time_t * const timep, const long offset,
 ** Re-entrant version of localtime.
 */
 extern "C" struct tm *
-localtime_r(const time_t *timep, struct tm *tmp)
+localtime_r(const time_t *__restrict timep, struct tm *__restrict tmp)
 {
 	tzset_guard.init ("tzset_guard")->acquire ();
 	tzset_unlocked();
@@ -1820,7 +1820,7 @@ gmtime(const time_t *const timep)
 */
 
 extern "C" struct tm *
-gmtime_r(const time_t * const timep, struct tm *tmp)
+gmtime_r(const time_t *__restrict const timep, struct tm *__restrict tmp)
 {
 	tmp = gmtsub(NULL, timep, 0L, tmp);
 
diff --git a/winsup/cygwin/miscfuncs.cc b/winsup/cygwin/miscfuncs.cc
index f6308b634..b2da91846 100644
--- a/winsup/cygwin/miscfuncs.cc
+++ b/winsup/cygwin/miscfuncs.cc
@@ -793,7 +793,7 @@ memset (void *s, int c, size_t n)
 }
 
 extern "C" void *
-memcpy(void *dest, const void *src, size_t n)
+memcpy(void *__restrict dest, const void *__restrict src, size_t n)
 {
   RtlCopyMemory (dest, src, n);
   return dest;
diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc
index 2b1e61442..91d847455 100644
--- a/winsup/cygwin/path.cc
+++ b/winsup/cygwin/path.cc
@@ -2989,7 +2989,7 @@ symlink_info::set (char *path)
 /* readlink system call */
 
 extern "C" ssize_t
-readlink (const char *path, char *buf, size_t buflen)
+readlink (const char *__restrict path, char *__restrict buf, size_t buflen)
 {
   if (buflen < 0)
     {
@@ -3413,7 +3413,7 @@ cygwin_conv_to_full_posix_path (const char *path, char *posix_path)
 /* The realpath function is required by POSIX:2008.  */
 
 extern "C" char *
-realpath (const char *path, char *resolved)
+realpath (const char *__restrict path, char *__restrict resolved)
 {
   /* Make sure the right errno is returned if path is NULL. */
   if (!path)
diff --git a/winsup/cygwin/strfuncs.cc b/winsup/cygwin/strfuncs.cc
index 07020649c..94ce82ce5 100644
--- a/winsup/cygwin/strfuncs.cc
+++ b/winsup/cygwin/strfuncs.cc
@@ -681,7 +681,7 @@ sys_mbstowcs_alloc (wchar_t **dst_p, int type, const char *src, size_t nms)
    NUL-terminate the destination string (s1).
    Return pointer to terminating byte in dst string.  */
 char * __stdcall
-strccpy (char *s1, const char **s2, char c)
+strccpy (char *__restrict s1, const char **__restrict s2, char c)
 {
   while (**s2 && **s2 != c)
     *s1++ = *((*s2)++);
diff --git a/winsup/cygwin/string.h b/winsup/cygwin/string.h
index 9426577a6..0a42f60eb 100644
--- a/winsup/cygwin/string.h
+++ b/winsup/cygwin/string.h
@@ -1,6 +1,6 @@
 /* string.h: Extra string defs
 
-   Copyright 2001, 2002, 2003, 2007, 2008, 2011, 2012 Red Hat, Inc.
+   Copyright 2001, 2002, 2003, 2007, 2008, 2011, 2012, 2013 Red Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -89,7 +89,8 @@ char * __stdcall cygwin_strupr (char *);
 
 #endif /* __INSIDE_CYGWIN__ */
 
-char *__stdcall strccpy (char *s1, const char **s2, char c);
+char *__stdcall strccpy (char *__restrict s1, const char **__restrict s2,
+			 char c);
 
 #ifdef __cplusplus
 }
diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc
index 0ad68cf82..ec79e57c1 100644
--- a/winsup/cygwin/syscalls.cc
+++ b/winsup/cygwin/syscalls.cc
@@ -1885,7 +1885,7 @@ stat_worker (path_conv &pc, struct stat *buf)
 }
 
 extern "C" int
-stat64 (const char *name, struct stat *buf)
+stat64 (const char *__restrict name, struct stat *__restrict buf)
 {
   syscall_printf ("entering");
   path_conv pc (name, PC_SYM_FOLLOW | PC_POSIX | PC_KEEP_HANDLE,
@@ -1894,7 +1894,8 @@ stat64 (const char *name, struct stat *buf)
 }
 
 extern "C" int
-_stat64_r (struct _reent *ptr, const char *name, struct stat *buf)
+_stat64_r (struct _reent *__restrict ptr, const char *__restrict name,
+	   struct stat *buf)
 {
   int ret;
 
@@ -1908,7 +1909,7 @@ EXPORT_ALIAS (stat64, stat)
 EXPORT_ALIAS (_stat64_r, _stat_r)
 #else
 extern "C" int
-stat (const char *name, struct stat *buf)
+stat (const char *__restrict name, struct stat *__restrict buf)
 {
   struct stat buf64;
   int ret = stat64 (name, &buf64);
@@ -1918,7 +1919,8 @@ stat (const char *name, struct stat *buf)
 }
 
 extern "C" int
-_stat_r (struct _reent *ptr, const char *name, struct stat *buf)
+_stat_r (struct _reent *__restrict ptr, const char *__restrict name,
+	 struct stat *__restrict buf)
 {
   int ret;
 
@@ -1930,7 +1932,7 @@ _stat_r (struct _reent *ptr, const char *name, struct stat *buf)
 
 /* lstat: Provided by SVR4 and 4.3+BSD, POSIX? */
 extern "C" int
-lstat64 (const char *name, struct stat *buf)
+lstat64 (const char *__restrict name, struct stat *__restrict buf)
 {
   syscall_printf ("entering");
   path_conv pc (name, PC_SYM_NOFOLLOW | PC_POSIX | PC_KEEP_HANDLE,
@@ -1943,7 +1945,7 @@ EXPORT_ALIAS (lstat64, lstat)
 #else
 /* lstat: Provided by SVR4 and 4.3+BSD, POSIX? */
 extern "C" int
-lstat (const char *name, struct stat *buf)
+lstat (const char *__restrict name, struct stat *__restrict buf)
 {
   struct stat buf64;
   int ret = lstat64 (name, &buf64);
@@ -4462,7 +4464,8 @@ fchownat (int dirfd, const char *pathname, uid_t uid, gid_t gid, int flags)
 }
 
 extern "C" int
-fstatat (int dirfd, const char *pathname, struct stat *st, int flags)
+fstatat (int dirfd, const char *__restrict pathname, struct stat *__restrict st,
+	 int flags)
 {
   tmp_pathbuf tp;
   myfault efault;
@@ -4592,7 +4595,8 @@ mknodat (int dirfd, const char *pathname, mode_t mode, dev_t dev)
 }
 
 extern "C" ssize_t
-readlinkat (int dirfd, const char *pathname, char *buf, size_t bufsize)
+readlinkat (int dirfd, const char *__restrict pathname, char *__restrict buf,
+	    size_t bufsize)
 {
   tmp_pathbuf tp;
   myfault efault;
diff --git a/winsup/cygwin/timer.cc b/winsup/cygwin/timer.cc
index 93b9cb592..5231499fb 100644
--- a/winsup/cygwin/timer.cc
+++ b/winsup/cygwin/timer.cc
@@ -1,6 +1,6 @@
 /* timer.cc
 
-   Copyright 2004, 2005, 2006, 2008, 2010, 2011, 2012 Red Hat, Inc.
+   Copyright 2004, 2005, 2006, 2008, 2010, 2011, 2012, 2013 Red Hat, Inc.
 
 This file is part of Cygwin.
 
@@ -295,7 +295,8 @@ timer_gettime (timer_t timerid, struct itimerspec *ovalue)
 }
 
 extern "C" int
-timer_create (clockid_t clock_id, struct sigevent *evp, timer_t *timerid)
+timer_create (clockid_t clock_id, struct sigevent *__restrict evp,
+	      timer_t *__restrict timerid)
 {
   myfault efault;
   if (efault.faulted (EFAULT))
@@ -318,8 +319,9 @@ timer_create (clockid_t clock_id, struct sigevent *evp, timer_t *timerid)
 }
 
 extern "C" int
-timer_settime (timer_t timerid, int flags, const struct itimerspec *value,
-	       struct itimerspec *ovalue)
+timer_settime (timer_t timerid, int flags,
+	       const struct itimerspec *__restrict value,
+	       struct itimerspec *__restrict ovalue)
 {
   timer_tracker *tt = (timer_tracker *) timerid;
   myfault efault;
@@ -374,7 +376,8 @@ fixup_timers_after_fork ()
 
 
 extern "C" int
-setitimer (int which, const struct itimerval *value, struct itimerval *ovalue)
+setitimer (int which, const struct itimerval *__restrict value,
+	   struct itimerval *__restrict ovalue)
 {
   int ret;
   if (which != ITIMER_REAL)
diff --git a/winsup/cygwin/times.cc b/winsup/cygwin/times.cc
index c9df29116..55157d389 100644
--- a/winsup/cygwin/times.cc
+++ b/winsup/cygwin/times.cc
@@ -158,7 +158,7 @@ totimeval (struct timeval *dst, PLARGE_INTEGER src, int sub, int flag)
 
 /* FIXME: Make thread safe */
 extern "C" int
-gettimeofday (struct timeval *tv, void *tzvp)
+gettimeofday (struct timeval *__restrict tv, void *__restrict tzvp)
 {
   struct timezone *tz = (struct timezone *) tzvp;
   static bool tzflag;