diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 92af3674e..de1165994 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -78,6 +78,16 @@ If your patch does not require interactions with a GUI or external processes,
 please consider adding unit tests for your code. Have a look at the existing
 test suite in the `tests` folder to see what kind of features are tested.
 
+Running tests
+-------------
+
+Be sure to test your changes thoroughly, never submit changes without running
+the code. At the very least, run the test suite and check that nothing broke.
+You can run the test suite by typing `make test` in the source directory.
+In order to run the test, you'll need to install nosetests and flake8:
+
+    pip3 install nose flake8
+
 Submitting your changes
 -----------------------