{{< alert tip >}}
Gatling 3.9 is not binary compatible with previous versions.
Any code compiled with a previous version must be recompiled in order to be executed with Gatling 3.9.
Changes listed below are only about source compatibility changes.
{{< /alert >}}

{{< alert tip >}}
We recommend that maven, gradle and sbt users upgrade their plugin version if their current version is lower than the one below:
* maven `io.gatling:gatling-maven-plugin:4.2.9`
* gradle `io.gatling.gradle:3.9.0.1`
* sbt `io.gatling:gatling-sbt:4.2.6`
{{< /alert >}}

## Core

We've upgraded [Pebble](https://github.com/PebbleTemplates/pebble) to 3.2.0. This release changes the main package from `com.mitchellbosecke` to `io.pebbletemplates`. As a result, if you're using custom Pebble extensions, they must be upgraded too in order to work with Gatling 3.9 and above.