docker node we use to build images uses docker <1.10 
see https://github.com/docker/docker/pull/18350
diff --git a/weekly.sh b/weekly.sh
index 0bdcb16..e615272 100755
--- a/weekly.sh
+++ b/weekly.sh
@@ -13,7 +13,7 @@
              --build-arg JENKINS_SHA=$JENKINS_SHA \
              --tag jenkinsci/jenkins:$JENKINS_VERSION .
 
-docker tag jenkinsci/jenkins:$JENKINS_VERSION jenkinsci/jenkins:latest
+docker tag -f jenkinsci/jenkins:$JENKINS_VERSION jenkinsci/jenkins:latest
 
 docker push jenkinsci/jenkins:$JENKINS_VERSION
 docker push jenkinsci/jenkins:latest