diff --git a/boot/zephyr/Kconfig b/boot/zephyr/Kconfig
index 33b5b8c..7ff8e16 100644
--- a/boot/zephyr/Kconfig
+++ b/boot/zephyr/Kconfig
@@ -38,8 +38,14 @@
 	help
 	  Enable serial recovery feature in mcuboot.
 
+config BOOT_MAX_IMG_SECTORS
+	int "max number of sectors per image slot"
+	default 128
+	help
+	  Maximum number of sectors that a swap upgrade can handle
+
 config BOOT_MAX_LINE_INPUT_LEN
-	int "cmd line max length" 
+	int "cmd line max length"
 	default 512
 	depends on MCUBOOT_SERIAL
 	help