diff --git a/.devdata.env.sample b/.devdata.env.sample
new file mode 100644
index 0000000..fd6013f
--- /dev/null
+++ b/.devdata.env.sample
@@ -0,0 +1,6 @@
+# Use this file as a template for .devdata.env
+
+### General
+
+# Path to RIOTBASE
+# RIOTBASE=/path/to/RIOT
diff --git a/.gitignore b/.gitignore
index 7a78a20..bd8661b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 test-report.xml
+.devdata.env
 
 #### joe made this: http://goel.io/joe
 
diff --git a/README.md b/README.md
index 533672b..8602c17 100644
--- a/README.md
+++ b/README.md
@@ -306,6 +306,17 @@ tox -- -k spec03 -k "task01 or task05"
 
 is identical to the first example.
 
+##### Using an env file to keep persistent environment variables
+
+Most tests require a set of user specific environment variable (path to
+RIOTBASE, LoRaWAN keys, etc). In order to keep these variables persistent, a
+.devdata.env file can be place in the root directory. For that, please make
+a copy of ".devdata.env.sample" and modify accordingly:
+
+```sh
+cp .devdata.env.sample .devdata.env
+```
+
 [pytest]: https://pytest.org
 [riotctrl]: https://pypi.org/project/riotctrl/
 [IoT-LAB saclay site]: https://www.iot-lab.info/deployment/saclay/
diff --git a/tox.ini b/tox.ini
index 700b178..2132c0f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,7 @@
 [tox]
 envlist = test,flake8,pylint
 skipsdist = True
+requires = tox-envfile
 
 [testenv]
 basepython = python3