diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index a8381ce05..b9c8ca3f9 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,8 @@
+Tue Aug  8 13:20:00 2000  Bob Wilson  <bwilson@tensilica.com>
+
+	* fhandler_serial.cc (tcsendbreak): "sleeptime" argument to usleep()
+	must be in units of microseconds, not milliseconds.
+
 Mon Aug  7 00:11:35 2000  Christopher Faylor <cgf@cygnus.com>
 
 	* include/cygwin/cygwin_dll.h: Remove extraneous (and incorrect)
diff --git a/winsup/cygwin/fhandler_serial.cc b/winsup/cygwin/fhandler_serial.cc
index 96d7793b2..6ceb71e31 100644
--- a/winsup/cygwin/fhandler_serial.cc
+++ b/winsup/cygwin/fhandler_serial.cc
@@ -285,7 +285,7 @@ fhandler_serial::close ()
 int
 fhandler_serial::tcsendbreak (int duration)
 {
-  unsigned int sleeptime = 300;
+  unsigned int sleeptime = 300000;
 
   if (duration > 0)
     sleeptime *= duration;