diff --git a/newlib/ChangeLog b/newlib/ChangeLog
index c214b6988..420354ef6 100644
--- a/newlib/ChangeLog
+++ b/newlib/ChangeLog
@@ -1,3 +1,14 @@
+2015-03-31  Corinna Vinschen  <vinschen@redhat.com>
+
+	* libc/time/local.h (_tzset_unlocked_r): Add prototype.
+	(_tzset_unlocked): Ditto.
+	* libc/time/tzset.c (_tzset_unlocked): New function, call
+	_tzset_unlocked_r.
+	(tzset): Lock and call _tzset_unlocked_r.
+	* libc/time/tzset_r (_tzset_unlocked_r): Remove locking and rename
+	from _tzset_r.
+	(_tzset_r): Lock and call _tzset_unlocked_r.
+
 2015-03-30  Craig Howland  <howland@LGSInnovations.com>
 
 	* libc/stdlib/setenv_r.c (_setenv_r): Remove tzset() call for TZ
diff --git a/newlib/libc/time/local.h b/newlib/libc/time/local.h
index 5fc3ddcb1..af5793af9 100644
--- a/newlib/libc/time/local.h
+++ b/newlib/libc/time/local.h
@@ -23,6 +23,9 @@ int         _EXFUN (__tzcalc_limits, (int __year));
 
 extern _CONST int __month_lengths[2][MONSPERYEAR];
 
+_VOID _EXFUN(_tzset_unlocked_r, (struct _reent *));
+_VOID _EXFUN(_tzset_unlocked, (_VOID));
+
 /* locks for multi-threading */
 #ifdef __SINGLE_THREAD__
 #define TZ_LOCK
diff --git a/newlib/libc/time/tzset.c b/newlib/libc/time/tzset.c
index d847a26b0..5c421a58e 100644
--- a/newlib/libc/time/tzset.c
+++ b/newlib/libc/time/tzset.c
@@ -67,8 +67,16 @@ Supporting OS subroutine required: None
 #include <time.h>
 #include "local.h"
 
+_VOID
+_DEFUN_VOID (_tzset_unlocked)
+{
+  _tzset_unlocked_r (_REENT);
+}
+
 _VOID
 _DEFUN_VOID (tzset)
 {
-  _tzset_r (_REENT);
+  TZ_LOCK;
+  _tzset_unlocked_r (_REENT);
+  TZ_UNLOCK;
 }
diff --git a/newlib/libc/time/tzset_r.c b/newlib/libc/time/tzset_r.c
index 2c5b72341..6c21e822e 100644
--- a/newlib/libc/time/tzset_r.c
+++ b/newlib/libc/time/tzset_r.c
@@ -14,7 +14,7 @@ static char __tzname_dst[11];
 static char *prev_tzenv = NULL;
 
 _VOID
-_DEFUN (_tzset_r, (reent_ptr),
+_DEFUN (_tzset_unlocked_r, (reent_ptr),
         struct _reent *reent_ptr)
 {
   char *tzenv;
@@ -25,24 +25,17 @@ _DEFUN (_tzset_r, (reent_ptr),
 
   if ((tzenv = _getenv_r (reent_ptr, "TZ")) == NULL)
       {
-	TZ_LOCK;
 	_timezone = 0;
 	_daylight = 0;
 	_tzname[0] = "GMT";
 	_tzname[1] = "GMT";
 	free(prev_tzenv);
 	prev_tzenv = NULL;
-	TZ_UNLOCK;
 	return;
       }
 
-  TZ_LOCK;
-
   if (prev_tzenv != NULL && strcmp(tzenv, prev_tzenv) == 0)
-    {
-      TZ_UNLOCK;
-      return;
-    }
+    return;
 
   free(prev_tzenv);
   prev_tzenv = _malloc_r (reent_ptr, strlen(tzenv) + 1);
@@ -54,10 +47,7 @@ _DEFUN (_tzset_r, (reent_ptr),
     ++tzenv;  
 
   if (sscanf (tzenv, "%10[^0-9,+-]%n", __tzname_std, &n) <= 0)
-    {
-      TZ_UNLOCK;
-      return;
-    }
+    return;
  
   tzenv += n;
 
@@ -74,10 +64,7 @@ _DEFUN (_tzset_r, (reent_ptr),
   ss = 0;
  
   if (sscanf (tzenv, "%hu%n:%hu%n:%hu%n", &hh, &n, &mm, &n, &ss, &n) < 1)
-    {
-      TZ_UNLOCK;
-      return;
-    }
+    return;
   
   tz->__tzrule[0].offset = sign * (ss + SECSPERMIN * mm + SECSPERHOUR * hh);
   _tzname[0] = __tzname_std;
@@ -88,7 +75,6 @@ _DEFUN (_tzset_r, (reent_ptr),
       _tzname[1] = _tzname[0];
       _timezone = tz->__tzrule[0].offset;
       _daylight = 0;
-      TZ_UNLOCK;
       return;
     }
   else
@@ -127,10 +113,7 @@ _DEFUN (_tzset_r, (reent_ptr),
 	{
 	  if (sscanf (tzenv, "M%hu%n.%hu%n.%hu%n", &m, &n, &w, &n, &d, &n) != 3 ||
 	      m < 1 || m > 12 || w < 1 || w > 5 || d > 6)
-	    {
-	      TZ_UNLOCK;
-	      return;
-	    }
+	    return;
 	  
 	  tz->__tzrule[i].ch = 'M';
 	  tz->__tzrule[i].m = m;
@@ -198,6 +181,13 @@ _DEFUN (_tzset_r, (reent_ptr),
   __tzcalc_limits (tz->__tzyear);
   _timezone = tz->__tzrule[0].offset;  
   _daylight = tz->__tzrule[0].offset != tz->__tzrule[1].offset;
+}
 
+_VOID
+_DEFUN (_tzset_r, (reent_ptr),
+        struct _reent *reent_ptr)
+{
+  TZ_LOCK;
+  _tzset_unlocked_r (reent_ptr);
   TZ_UNLOCK;
 }
diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 72d15278c..79ae5a9a1 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,7 @@
+2015-03-31  Corinna Vinschen  <corinna@vinschen.de>
+
+	* localtime.cc (tzset_unlocked): Export as _tzset_unlocked.
+
 2015-03-30  Yaakov Selkowitz  <yselkowi@redhat.com>
 
 	* common.din (__gnu_basename): Export.
diff --git a/winsup/cygwin/localtime.cc b/winsup/cygwin/localtime.cc
index ca58b65e1..d57a020b5 100644
--- a/winsup/cygwin/localtime.cc
+++ b/winsup/cygwin/localtime.cc
@@ -500,7 +500,11 @@ static int		tzload(timezone_t sp, const char * name,
 				int doextend);
 static int		tzparse(timezone_t sp, const char * name,
 				int lastditch);
+#ifdef __CYGWIN__
+extern "C" void		tzset_unlocked(void);
+#else
 static void		tzset_unlocked(void);
+#endif
 static long		leapcorr(const timezone_t sp, time_t * timep);
 
 static timezone_t lclptr;
@@ -1613,6 +1617,9 @@ tzsetwall (void)
 
 static NO_COPY muto tzset_guard;
 
+#ifdef __CYGWIN__
+extern "C"
+#else
 #ifndef STD_INSPIRED
 /*
 ** A non-static declaration of tzsetwall in a system header file
@@ -1620,6 +1627,7 @@ static NO_COPY muto tzset_guard;
 */
 static
 #endif /* !defined STD_INSPIRED */
+#endif
 void
 tzset_unlocked(void)
 {
@@ -1663,6 +1671,8 @@ tzset_unlocked(void)
 	settzname();
 }
 
+EXPORT_ALIAS (tzset_unlocked, _tzset_unlocked)
+
 extern "C" void
 tzset(void)
 {