diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc
index 1033a2087..4aa9a4dd1 100644
--- a/winsup/cygwin/fhandler_tty.cc
+++ b/winsup/cygwin/fhandler_tty.cc
@@ -2063,6 +2063,7 @@ fhandler_pty_master::pty_master_fwd_thread ()
 		memmove (&outbuf[start_at], &outbuf[i+1], rlen-i-1);
 		rlen = wlen = start_at + rlen - i - 1;
 		state = 0;
+		i = start_at - 1;
 		continue;
 	      }
 	    else