diff --git a/.coveragerc b/.coveragerc
index 1b9e8d18ea..38a34a15a4 100644
--- a/.coveragerc
+++ b/.coveragerc
@@ -1,6 +1,7 @@
 # .coveragerc to control coverage.py
 [run]
 branch = True
+concurrency = multiprocessing,thread
 
 source = wagtail
 
diff --git a/.gitignore b/.gitignore
index 9519fac54f..121204e073 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,6 +2,7 @@
 *.pyc
 .DS_Store
 /.coverage
+/.coverage.*
 /dist/
 /build/
 /MANIFEST