diff --git a/en/SUMMARY.md b/en/SUMMARY.md
index 0b771681b..1d53ac824 100644
--- a/en/SUMMARY.md
+++ b/en/SUMMARY.md
@@ -59,4 +59,5 @@
   * [ualberta.xml](messages/ualberta.md)
   * [uAvionix.xml](messages/uAvionix.md)
 * [Contributing](contributing/contributing.md)
+  * [Testing](guide/testing.md)
 * [Support](about/support.md)
\ No newline at end of file
diff --git a/en/guide/testing.md b/en/guide/testing.md
new file mode 100644
index 000000000..514bbbca1
--- /dev/null
+++ b/en/guide/testing.md
@@ -0,0 +1,18 @@
+# Testing
+
+## Changes to Mavgen
+
+Changes to the mavgen generator (in [ArduPilot/pymavlink](https://github.com/ArduPilot/pymavlink)) are tested on every PR prior to acceptance into the master branch.
+
+You can run the test code yourself in Ubuntu.
+1. Install additional dependencies for gtest:
+   ```sh
+   sudo apt-get install cmake libgtest-dev
+   ```
+1. Run the test generator from the pymavlink directory:
+   ```sh
+   cd pymavlink
+   ./test_generator.sh
+   ```
+   > **Tip** The tests require message definitions in **../message_definitions/** (i.e. at the level above the **pymavlink** directory).
+     This is how things are set up when you're running the tests from the *mavlink* repo.