diff --git a/tox.ini b/tox.ini
index b00833e7..1edcfe26 100644
--- a/tox.ini
+++ b/tox.ini
@@ -16,7 +16,6 @@ pass_env = WEBSOCKETS_*
 
 [testenv:coverage]
 commands =
-    python -m coverage erase
     python -m coverage run --source {envsitepackagesdir}/websockets,tests -m unittest {posargs}
     python -m coverage report --show-missing --fail-under=100
 deps = coverage