diff --git a/scripts/kwboot.c b/scripts/kwboot.c
index 3ab26cd..4c6b19a 100644
--- a/scripts/kwboot.c
+++ b/scripts/kwboot.c
@@ -264,10 +264,11 @@
 }
 
 static int
-kwboot_bootmsg(int tty, void *msg)
+kwboot_bootmsg(int tty, void *msg, unsigned num_nacks)
 {
 	int rc;
 	char c;
+	unsigned saw_nacks = 0;
 
 	if (msg == NULL)
 		kwboot_printv("Please reboot the target into UART boot mode...");
@@ -295,11 +296,13 @@
 				kwboot_printv("\\x%02hhx", c);
 
 			rc = kwboot_tty_recv(tty, &c, 1, KWBOOT_MSG_RSP_TIMEO);
+
+			saw_nacks = 0;
 		}
 
-	} while (rc || c != NAK);
+	} while (rc || c != NAK || (++saw_nacks < num_nacks));
 
-	kwboot_printv("\nGot expected NAK\n");
+	kwboot_printv("\nGot expected NAKs\n");
 
 	return rc;
 }
@@ -736,6 +739,7 @@
 	void *bootmsg;
 	void *debugmsg;
 	void *img;
+	unsigned num_nacks = 1;
 	size_t size;
 	speed_t speed;
 
@@ -752,7 +756,7 @@
 	kwboot_verbose = isatty(STDOUT_FILENO);
 
 	do {
-		int c = getopt(argc, argv, "b:dfhtB:D:");
+		int c = getopt(argc, argv, "b:dfhtn:B:D:");
 		if (c < 0)
 			break;
 
@@ -779,6 +783,10 @@
 			force = 1;
 			break;
 
+		case 'n':
+			num_nacks = atoi(optarg);
+			break;
+
 		case 'B':
 			speed = kwboot_tty_speed(atoi(optarg));
 			if (speed == -1)
@@ -828,7 +836,7 @@
 			goto out;
 		}
 	} else {
-		rc = kwboot_bootmsg(tty, bootmsg);
+		rc = kwboot_bootmsg(tty, bootmsg, num_nacks);
 		if (rc) {
 			perror("bootmsg");
 			goto out;