diff --git a/.drone.yml b/.drone.yml
index 179e930..f6d7aa3 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -9,7 +9,7 @@ steps:
     commands:
       - pip install -U pip
       - pip install mypy flake8 black
-        # - black --check .
+      - black --check .
       - flake8 activitypub.py
       - mypy --ignore-missing-imports .
 
diff --git a/activitypub.py b/activitypub.py
index 4f7104a..db5a977 100644
--- a/activitypub.py
+++ b/activitypub.py
@@ -58,7 +58,7 @@ def _remove_id(doc: ap.ObjectType) -> ap.ObjectType:
     """Helper for removing MongoDB's `_id` field."""
     doc = doc.copy()
     if "_id" in doc:
-        del (doc["_id"])
+        del doc["_id"]
     return doc
 
 
@@ -425,7 +425,7 @@ class MicroblogPubBackend(Backend):
                 update["$set"][f"{update_prefix}{k}"] = v
 
         if len(update["$unset"]) == 0:
-            del (update["$unset"])
+            del update["$unset"]
 
         print(f"updating note from outbox {obj!r} {update}")
         logger.info(f"updating note from outbox {obj!r} {update}")
diff --git a/app.py b/app.py
index d90502c..f732202 100644
--- a/app.py
+++ b/app.py
@@ -850,7 +850,11 @@ def _build_thread(data, include_children=True):  # noqa: C901
             replies.append(dat)
         else:
             # Make a Note/Question/... looks like a Create
-            dat = {"activity": {"object": dat["activity"]}, "meta": dat["meta"], "_id": dat["_id"]}
+            dat = {
+                "activity": {"object": dat["activity"]},
+                "meta": dat["meta"],
+                "_id": dat["_id"],
+            }
             replies.append(dat)
 
     replies = sorted(replies, key=lambda d: d["activity"]["object"]["published"])
@@ -1341,7 +1345,10 @@ def admin_lookup():
 @login_required
 def admin_thread():
     data = DB.activities.find_one(
-        {"type": ActivityType.CREATE.value, "activity.object.id": request.args.get("oid")}
+        {
+            "type": ActivityType.CREATE.value,
+            "activity.object.id": request.args.get("oid"),
+        }
     )
 
     if not data:
@@ -1385,7 +1392,13 @@ def admin_new():
         content = f"@{actor.preferredUsername}@{domain} "
         thread = _build_thread(data)
 
-    return render_template("new.html", reply=reply_id, content=content, thread=thread, emojis=EMOJIS.split(" "))
+    return render_template(
+        "new.html",
+        reply=reply_id,
+        content=content,
+        thread=thread,
+        emojis=EMOJIS.split(" "),
+    )
 
 
 @app.route("/admin/notifications")
diff --git a/config.py b/config.py
index c3967d0..7b6d6ea 100644
--- a/config.py
+++ b/config.py
@@ -108,7 +108,10 @@ def create_indexes():
     DB.activities.create_index([("activity.object.id", pymongo.ASCENDING)])
     DB.activities.create_index([("meta.thread_root_parent", pymongo.ASCENDING)])
     DB.activities.create_index(
-        [("meta.thread_root_parent", pymongo.ASCENDING), ("meta.deleted", pymongo.ASCENDING)]
+        [
+            ("meta.thread_root_parent", pymongo.ASCENDING),
+            ("meta.deleted", pymongo.ASCENDING),
+        ]
     )
     DB.activities.create_index(
         [("activity.object.id", pymongo.ASCENDING), ("meta.deleted", pymongo.ASCENDING)]
diff --git a/tests/federation_test.py b/tests/federation_test.py
index 6fa34f3..df4499e 100644
--- a/tests/federation_test.py
+++ b/tests/federation_test.py
@@ -32,15 +32,13 @@ class Instance(object):
     def _do_req(self, url):
         """Used to parse collection."""
         url = url.replace(self.docker_url, self.host_url)
-        resp = requests.get(url, headers={'Accept': 'application/activity+json'})
+        resp = requests.get(url, headers={"Accept": "application/activity+json"})
         resp.raise_for_status()
         return resp.json()
 
     def _parse_collection(self, payload=None, url=None):
         """Parses a collection (go through all the pages)."""
-        return parse_collection(
-            url=url, payload=payload, fetcher=self._do_req,
-        )
+        return parse_collection(url=url, payload=payload, fetcher=self._do_req)
 
     def ping(self):
         """Ensures the homepage is reachable."""
@@ -207,14 +205,10 @@ class Instance(object):
 
 def _instances() -> Tuple[Instance, Instance]:
     """Initializes the client for the two test instances."""
-    instance1 = Instance(
-        "instance1", "http://docker:5006", "http://instance1_web:5005"
-    )
+    instance1 = Instance("instance1", "http://docker:5006", "http://instance1_web:5005")
     instance1.ping()
 
-    instance2 = Instance(
-        "instance2", "http://docker:5007", "http://instance2_web:5005"
-    )
+    instance2 = Instance("instance2", "http://docker:5007", "http://instance2_web:5005")
     instance2.ping()
 
     # Return the DB
diff --git a/utils/lookup.py b/utils/lookup.py
index 3e97bfb..4f1e121 100644
--- a/utils/lookup.py
+++ b/utils/lookup.py
@@ -10,7 +10,7 @@ from little_boxes.webfinger import get_actor_url
 def lookup(url: str) -> ap.BaseActivity:
     """Try to find an AP object related to the given URL."""
     try:
-        if url.startswith('@'):
+        if url.startswith("@"):
             actor_url = get_actor_url(url)
             if actor_url:
                 return ap.fetch_remote_activity(actor_url)
diff --git a/utils/media.py b/utils/media.py
index 06559f7..0dfe44c 100644
--- a/utils/media.py
+++ b/utils/media.py
@@ -15,7 +15,7 @@ def load(url, user_agent):
     """Initializes a `PIL.Image` from the URL."""
     with requests.get(url, stream=True, headers={"User-Agent": user_agent}) as resp:
         resp.raise_for_status()
-        if not resp.headers.get('content-type').startswith('image/'):
+        if not resp.headers.get("content-type").startswith("image/"):
             raise ValueError(f"bad content-type {resp.headers.get('content-type')}")
 
         resp.raw.decode_content = True
diff --git a/utils/opengraph.py b/utils/opengraph.py
index df59732..521b645 100644
--- a/utils/opengraph.py
+++ b/utils/opengraph.py
@@ -48,7 +48,7 @@ def fetch_og_metadata(user_agent, links):
             logger.debug(f"skipping {l}")
             continue
 
-        r.encoding = 'UTF-8'
+        r.encoding = "UTF-8"
         html = r.text
         try:
             data = dict(opengraph.OpenGraph(html=html))