diff --git a/winsup/cygwin/release/2.1.0 b/winsup/cygwin/release/2.1.0
index aca69cdf3..1b9e19f97 100644
--- a/winsup/cygwin/release/2.1.0
+++ b/winsup/cygwin/release/2.1.0
@@ -33,3 +33,7 @@ Bug Fixes
   Addresses: https://cygwin.com/ml/cygwin/2015-06/msg00384.html
 
 - Fix a crash on 64 bit XP/2003 when opening /proc/$PID/maps.
+
+- Apparently on some Windows systems timezones differ in case
+  from the standard.  Fix the tzset tool to check case-insensitive.
+  Addresses: https://cygwin.com/ml/cygwin/2015-07/msg00113.html
diff --git a/winsup/utils/ChangeLog b/winsup/utils/ChangeLog
index 5a68a40cd..db6049bb1 100644
--- a/winsup/utils/ChangeLog
+++ b/winsup/utils/ChangeLog
@@ -1,3 +1,7 @@
+2015-07-08  Corinna Vinschen  <corinna@vinschen.de>
+
+	* tzset.c (main): Check timezone and country case-insensitive.
+
 2015-06-07  Jon Turney  <jon.turney@dronecode.org.uk>
 
 	* strace.cc (proc_child): Log process and thread create and exit,
diff --git a/winsup/utils/tzset.c b/winsup/utils/tzset.c
index 2b3f413be..0e22f44df 100644
--- a/winsup/utils/tzset.c
+++ b/winsup/utils/tzset.c
@@ -207,11 +207,11 @@ main (int argc, char **argv)
   /* Now iterate over the mapping table and find the right entry. */
   for (idx = 0; idx < TZMAP_SIZE; ++idx)
     {
-      if (!wcscmp (keyname, tzmap[idx].win_tzkey))
+      if (!wcscasecmp (keyname, tzmap[idx].win_tzkey))
 	{
 	  if (gotit < 0)
 	    gotit = idx;
-	  if (!wcscmp (country, tzmap[idx].country))
+	  if (!wcscasecmp (country, tzmap[idx].country))
 	    break;
 	}
       else if (gotit >= 0)