diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index bd28a343e..d28b9ac6a 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,7 @@
+2005-08-05  Vaclav Haisman  <v.haisman@sh.cvut.cz>
+
+	* fhandler_tty.cc (fhandler_tty_slave::tcflush): Return either 0 or -1.
+
 2005-08-05  Corinna Vinschen  <corinna@vinschen.de>
 
 	* thread.cc (pthread_cond_timedwait): Check abstime for validity
diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc
index 3d5a567df..a644c0f78 100644
--- a/winsup/cygwin/fhandler_tty.cc
+++ b/winsup/cygwin/fhandler_tty.cc
@@ -1051,7 +1051,7 @@ fhandler_tty_slave::tcflush (int queue)
     {
       size_t len = UINT_MAX;
       read (NULL, len);
-      ret = ((int) len) >= 0;
+      ret = ((int) len) >= 0 ? 0 : -1;
     }
   if (queue == TCOFLUSH || queue == TCIOFLUSH)
     {