diff --git a/container/Makefile b/container/Makefile
index 97b33df..9e662dc 100644
--- a/container/Makefile
+++ b/container/Makefile
@@ -1,9 +1,5 @@
-ifeq ($(IMAGE_SRC),)
-IMAGE_SRC += docker://$(IMAGE_REPO)/$(IMAGE_NAME):$(IMAGE_TAG)
-endif
-
 $(IMAGE_NAME)-$(IMAGE_TAG):
-	skopeo copy $(IMAGE_SRC) oci:$(IMAGE_NAME)-$(IMAGE_TAG)
+	skopeo copy $(if $(IMAGE_SRC),$(IMAGE_SRC),docker://$(IMAGE_REPO)/$(IMAGE_NAME):$(IMAGE_TAG)) oci:$(IMAGE_NAME)-$(IMAGE_TAG)
 
 install-deps:
 	$(install_pkg) skopeo