diff --git a/include/image-commands.mk b/include/image-commands.mk
index ae01706b14..05d36093d3 100644
--- a/include/image-commands.mk
+++ b/include/image-commands.mk
@@ -332,7 +332,7 @@ metadata_json = \
 
 define Build/append-metadata
 	$(if $(SUPPORTED_DEVICES),-echo $(call metadata_json,$(SUPPORTED_DEVICES)) | fwtool -I - $@)
-	[ ! -s "$(BUILD_KEY)" -o ! -s "$(BUILD_KEY).ucert" ] || { \
+	[ ! -s "$(BUILD_KEY)" -o ! -s "$(BUILD_KEY).ucert" -o ! -s "$@" ] || { \
 		cp "$(BUILD_KEY).ucert" "$@.ucert" ;\
 		usign -S -m "$@" -s "$(BUILD_KEY)" -x "$@.sig" ;\
 		ucert -A -c "$@.ucert" -x "$@.sig" ;\