diff --git a/.gitignore b/.gitignore
index 7f8b3a1c..cc2606fa 100644
--- a/.gitignore
+++ b/.gitignore
@@ -99,3 +99,6 @@ generated/
 MANIFEST
 deb_build
 rtr.cvs
+
+# pytest parallel
+.coverage*
diff --git a/CONTRIBUTING.txt b/CONTRIBUTING.txt
index 0b4b1beb..5a904958 100644
--- a/CONTRIBUTING.txt
+++ b/CONTRIBUTING.txt
@@ -49,3 +49,12 @@ Please use the following guidelines when preparing changes:
 
         QObject subclasses that implement new signals should also describe 
         these in a similar table.
+
+* Setting up a test environment.
+
+    Tests for a module should ideally cover all code in that module,
+    i.e., statement coverage should be at 100%.
+
+    To measure the test coverage, install py.test, pytest-cov and pytest-xdist.
+    Then run 'py.test --cov -n 4' to run the test suite with coverage on 4 cores.
+