diff --git a/tox.ini b/tox.ini
index c22c7d2d..ef5eaa33 100644
--- a/tox.ini
+++ b/tox.ini
@@ -29,9 +29,9 @@ setenv =
     env37: JEDI_TEST_ENVIRONMENT=37
 commands =
     pytest {posargs}
-[testenv:cov]
+[testenv:cov-py37]
 commands =
-    coverage run --source jedi -m pytest
+    coverage run --source jedi -m pytest {posargs}
     coverage report
 [testenv:sith]
 commands =