diff --git a/Makefile b/Makefile
index 9675b8ccb0..b2b7fdd364 100755
--- a/Makefile
+++ b/Makefile
@@ -6,7 +6,7 @@ init:
 	pip install -e '.[dev]'
 
 test:
-	pytest --cov samtranslator --cov-report term-missing --cov-fail-under 95 tests/*
+	pytest --cov samtranslator --cov-report term-missing --cov-fail-under 95 -n auto tests/*
 
 test-cov-report:
 	pytest --cov samtranslator --cov-report term-missing --cov-report html --cov-fail-under 95 tests/*
diff --git a/requirements/dev.txt b/requirements/dev.txt
index 1424f80d6e..ee58bcfa24 100644
--- a/requirements/dev.txt
+++ b/requirements/dev.txt
@@ -2,6 +2,7 @@ coverage~=5.3
 flake8~=3.8.4
 tox~=3.20.1
 pytest-cov~=2.10.1
+pytest-xdist~=1.34.0  # pytest-xdist 2 is not compatible with Python 2.7
 pylint>=1.7.2,<2.0
 pyyaml~=5.4