diff --git a/README.md b/README.md
index 1d06d98..8dc7356 100644
--- a/README.md
+++ b/README.md
@@ -193,6 +193,8 @@ You can find some more information about the SProcWrapper in our various Zalando
 * http://tech.zalando.com/blog/zalando-stored-procedure-wrapper-part-i/
 * http://tech.zalando.com/blog/files/2013/04/jug_dortmund_april_2013.pdf
 
+🚨 Upgrading from 2.x to 3.x? Please be aware that default scanning package for custom objectTransformer has changed from `de.zalando` to `org.zalando`.
+
 ## Contributing
 
 See [contributing guideline](CONTRIBUTING.md).