diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 5f092f7ae..3707a8a51 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,8 @@
+2007-07-04  Corinna Vinschen  <corinna@vinschen.de>
+
+	* include/cygwin/time.h: Switch to timezone variable by default.  Add
+	comment.
+
 2007-06-29  Corinna Vinschen  <corinna@vinschen.de>
 
 	* cygwin.din: Export fdopendir.
diff --git a/winsup/cygwin/include/cygwin/time.h b/winsup/cygwin/include/cygwin/time.h
index 4a482d78f..2f84505f5 100644
--- a/winsup/cygwin/include/cygwin/time.h
+++ b/winsup/cygwin/include/cygwin/time.h
@@ -29,7 +29,9 @@ time_t __cdecl timegm (struct tm *);
 #   define daylight _daylight
 # endif
 
-# ifndef timezonevar
+/* The timezone function is only kept for backward compatibility.
+   POSIX expects the timezone variable as XSI extension. */
+# ifdef __timezonefunc__
 char __cdecl *timezone (void);
 # elif !defined(timezone)
 #   define timezone _timezone