diff --git a/Dockerfile b/Dockerfile
index 8f647fd..c431580 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -7,8 +7,9 @@ RUN \
 
 FROM scratch
 
-ARG GIT_COMMIT=
-ARG BUILD_DATE=
+# these values will be replaced by the automatic build pipeline.
+ARG GIT_COMMIT=unknown
+ARG BUILD_DATE=0001-01-01T00:00:00Z
 # Image annotations, see https://github.com/opencontainers/image-spec/blob/master/annotations.md
 LABEL \
     org.opencontainers.image.vendor=Zombi \