diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 2cb8e8899..25c789dc1 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,7 @@
+2002-12-30  Christopher Faylor  <cgf@redhat.com>
+
+	* windows.cc (setitimer): Return ENOSYS on invalid argument.
+
 2002-12-28  Christopher Faylor  <cgf@redhat.com>
 
 	* fhandler_termios.cc (fhandler_termios::line_edit): Perform echo
diff --git a/winsup/cygwin/window.cc b/winsup/cygwin/window.cc
index 80e95a143..55bc369c0 100644
--- a/winsup/cygwin/window.cc
+++ b/winsup/cygwin/window.cc
@@ -148,7 +148,7 @@ setitimer (int which, const struct itimerval *value, struct itimerval *oldvalue)
 
   if (which != ITIMER_REAL)
     {
-      set_errno (EINVAL);
+      set_errno (ENOSYS);
       return -1;
     }
   /* Check if we will wrap */