pull the image to tag, in case it was built before
diff --git a/publish.sh b/publish.sh
index 4fc899f..5af7683 100755
--- a/publish.sh
+++ b/publish.sh
@@ -19,6 +19,8 @@
     local from="jenkinsci/jenkins:$1"
     local to="jenkinsci/jenkins:$2"
     local out
+
+    docker pull "$from"
     if out=$(docker tag -f "$from" "$to" 2>&1); then
         echo "$out"
     else