diff --git a/tests/README.md b/tests/README.md
index 75cb33e..0593eb3 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -9,3 +9,8 @@ where:
 - `-failfast` makes the test stop after first failure
 - `-count 1` is to avoid Go test caching for example when testing a rebuilt snap
 
+## Environment variables 
+
+Some environment variables can modify the test functionality. Refer to these in
+[the documentation](https://pkg.go.dev/github.com/canonical/matter-snap-testing/env)
+of the `matter-snap-testing` Go package.