diff --git a/tty.c b/tty.c
index 1ecb0e515..60098501d 100644
--- a/tty.c
+++ b/tty.c
@@ -1158,8 +1158,17 @@ static int dump_one_pty(int lfd, u32 id, const struct fd_parms *p)
 	 * we don't check for errors here since it makes
 	 * no sense anyway, the buffered data is not handled
 	 * properly yet.
+	 *
+	 * Note as well that if we have only one peer here
+	 * the external end might be sending the data to us
+	 * again and again while kernel buffer is not full,
+	 * this might lead to endless SIGTTOU signal delivery
+	 * to the dumpee, ruining checkpoint procedure.
+	 *
+	 * So simply do not flush the line while we dump
+	 * parameters tty never was being a guaranteed delivery
+	 * transport anyway.
 	 */
-	ioctl(lfd, TCFLSH, TCIOFLUSH);
 
 	if (!tty_test_and_set(e.tty_info_id, tty_bitmap))
 		ret = dump_pty_info(lfd, e.tty_info_id, p, major, index);