diff --git a/meta-digi-arm/recipes-digi/trustfence/trustfence-sign-tools/trustfence-sign-artifact.sh b/meta-digi-arm/recipes-digi/trustfence/trustfence-sign-tools/trustfence-sign-artifact.sh
index 98b8db448..1c9822bbe 100755
--- a/meta-digi-arm/recipes-digi/trustfence/trustfence-sign-tools/trustfence-sign-artifact.sh
+++ b/meta-digi-arm/recipes-digi/trustfence/trustfence-sign-tools/trustfence-sign-artifact.sh
@@ -83,6 +83,10 @@ if [ -z "${CONFIG_SIGN_KEYS_PATH}" ]; then
 	exit 1
 fi
 [ -d "${CONFIG_SIGN_KEYS_PATH}" ] || mkdir "${CONFIG_SIGN_KEYS_PATH}"
+if [ -z "${CONFIG_SIGN_MODE}" ]; then
+	echo "Undefined CONFIG_SIGN_MODE";
+	exit 1
+fi
 
 if [ "${CONFIG_SIGN_MODE}" = "HAB" ]; then
 	if [ -n "${CONFIG_DEK_PATH}" ]; then