diff --git a/samples/mcuboot_config/mcuboot_config.template.h b/samples/mcuboot_config/mcuboot_config.template.h
index 14ad218..3038a93 100644
--- a/samples/mcuboot_config/mcuboot_config.template.h
+++ b/samples/mcuboot_config/mcuboot_config.template.h
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2018 Open Source Foundries Limited
+ * Copyright (c) 2019 Arm Limited
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -82,6 +83,10 @@
  * as desirable. */
 #define MCUBOOT_MAX_IMG_SECTORS 128
 
+/* Default number of separately updateable images; change in case of
+ * multiple images. */
+#define MCUBOOT_IMAGE_NUMBER 1
+
 /*
  * Logging
  */