diff --git a/sys/dev/altera/jtag_uart/altera_jtag_uart_tty.c b/sys/dev/altera/jtag_uart/altera_jtag_uart_tty.c
index ad5b8a41bdc5..18fb8cd93966 100644
--- a/sys/dev/altera/jtag_uart/altera_jtag_uart_tty.c
+++ b/sys/dev/altera/jtag_uart/altera_jtag_uart_tty.c
@@ -67,7 +67,7 @@ static struct ttydevsw aju_ttydevsw = {
  * When polling for the AC bit, the number of times we have to not see it
  * before assuming JTAG has disappeared on us.  By default, one second.
  */
-#define	AJU_JTAG_MAXMISS		5
+#define	AJU_JTAG_MAXMISS		10
 
 /*
  * Polling intervals for input/output and JTAG connection events.