diff --git a/README.md b/README.md
index 734434d..2a32e4b 100644
--- a/README.md
+++ b/README.md
@@ -330,7 +330,7 @@ django.setup()
 
 ## Running project tests locally
 
-Install the dev dependencies with `pip install -e '.[dev]'` and then run `tox`.
+Install the dev dependencies with `pip install -e '.[dev]'` and then run `python -m pytest`.
 
 
 ## License
diff --git a/django_dramatiq/admin.py b/django_dramatiq/admin.py
index 6abd826..1b4fed1 100644
--- a/django_dramatiq/admin.py
+++ b/django_dramatiq/admin.py
@@ -42,8 +42,8 @@ def message_details(self, instance):
         # kwargs payload when a non json encoder is in use
         kwargs_encoder = DjangoDramatiqConfig.select_encoder()
         if not isinstance(kwargs_encoder, JSONEncoder):
-            for k,v in message_dict['kwargs'].items():
-                message_dict['kwargs'][k] = f"<{v}>"
+            for k, v in message_dict["kwargs"].items():
+                message_dict["kwargs"][k] = f"<{v}>"
 
         message_details = json.dumps(message_dict, indent=4)
         return mark_safe("<pre>%s</pre>" % message_details)
diff --git a/tests/conftest.py b/tests/conftest.py
index 7aa1c80..d96ea0b 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -10,6 +10,7 @@ def broker():
     yield broker
     broker.middleware = middleware
     broker.flush_all()
+    broker.actors.clear()
 
 
 @pytest.fixture