diff --git a/src/macros.mk b/src/macros.mk
index 937ca8b..a64c404 100644
--- a/src/macros.mk
+++ b/src/macros.mk
@@ -43,7 +43,9 @@ define build
 			--target $(TARGET) \
 			$(EXTRA_ARGS) \
 			$(NOCACHE_FLAG) \
+			-f src/$(CATEGORY)/$(NAME)/Containerfile \
 			src/$(CATEGORY)/$(NAME) \
+			&& tar -tf $(basename $@).tar \
 			&& gzip < $(basename $@).tar > $@ \
 			&& rm $(basename $@).tar \
 			&& gunzip -c $@ | docker load; \