diff --git a/Dockerfile b/Dockerfile
index f5c7285..9565e3a 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -13,7 +13,7 @@ RUN apk --no-cache add \
 WORKDIR /app
 
 COPY ./requirements /app/requirements
-RUN pip install pip setuptools -U
+RUN pip install pip setuptools==47.1.1
 RUN pip install -r requirements/production.txt
 
 
diff --git a/bin/docker_start.sh b/bin/docker_start.sh
index e286650..a4177f3 100755
--- a/bin/docker_start.sh
+++ b/bin/docker_start.sh
@@ -2,12 +2,21 @@
 
 set -ex
 
+# Wait for the database container
+# See: https://docs.docker.com/compose/startup-order/
+export PGHOST=${DB_HOST:-db}
+export PGPORT=${DB_PORT:-5432}
+
 fixtures_dir=${FIXTURES_DIR:-/app/fixtures}
 
 uwsgi_port=${UWSGI_PORT:-8000}
 
-# Wait for required services
-${SCRIPTPATH}/wait_for_db.sh
+until pg_isready; do
+  >&2 echo "Waiting for database connection..."
+  sleep 1
+done
+
+>&2 echo "Database is up."
 
 # Apply database migrations
 >&2 echo "Apply database migrations"
diff --git a/bin/wait_for_db.sh b/bin/wait_for_db.sh
deleted file mode 100644
index 8cdf20d..0000000
--- a/bin/wait_for_db.sh
+++ /dev/null
@@ -1,17 +0,0 @@
-#!/bin/sh
-
-set -e
-
-# Wait for the database container
-# See: https://docs.docker.com/compose/startup-order/
-db_host=${DB_HOST:-db}
-db_user=${DB_USER:-postgres}
-db_password=${DB_PASSWORD}
-db_port=${DB_PORT:-5432}
-
-until PGPORT=$db_port PGPASSWORD=$db_password psql -h "$db_host" -U "$db_user" -c '\q'; do
-  >&2 echo "Waiting for database connection..."
-  sleep 1
-done
-
->&2 echo "Database is up."
diff --git a/requirements/base.txt b/requirements/base.txt
index 7b26144..c914d7d 100644
--- a/requirements/base.txt
+++ b/requirements/base.txt
@@ -6,7 +6,7 @@
 #
 certifi==2019.9.11        # via requests
 chardet==3.0.4            # via requests
-click==7.0                # via pip-tools
+click==7.1.2              # via pip-tools
 coreapi==2.3.3            # via drf-yasg
 coreschema==0.0.4         # via coreapi, drf-yasg
 django-better-admin-arrayfield==1.0.4
@@ -32,7 +32,7 @@ jinja2==2.10.3            # via coreschema
 markdown==3.1.1
 markupsafe==1.1.1         # via jinja2
 oyaml==0.9                # via vng-api-common
-pip-tools==4.2.0
+pip-tools==5.3.1
 psycopg2==2.8.3
 pyjwt==1.7.1              # via gemma-zds-client, vng-api-common
 python-dateutil==2.8.0
diff --git a/requirements/ci.txt b/requirements/ci.txt
index 1705dba..77a198c 100644
--- a/requirements/ci.txt
+++ b/requirements/ci.txt
@@ -5,15 +5,15 @@
 #    pip-compile --no-index --output-file requirements/ci.txt requirements/base.txt requirements/dev.txt requirements/ci.in
 #
 appdirs==1.4.3
-attrs==19.3.0
 beautifulsoup4==4.8.1
-black==19.10b0
+black==20.8b1
 certifi==2019.9.11
 chardet==3.0.4
-click==7.0
+click==7.1.2
 coreapi==2.3.3
 coreschema==0.0.4
 coverage==4.5.4
+dataclasses==0.6
 django-better-admin-arrayfield==1.0.4
 django-choices==1.7.0
 django-cors-middleware==1.4.0
@@ -44,9 +44,10 @@ itypes==1.1.0
 jinja2==2.10.3
 markdown==3.1.1
 markupsafe==1.1.1
+mypy-extensions==0.4.3
 oyaml==0.9
 pathspec==0.6.0
-pip-tools==4.2.0
+pip-tools==5.3.1
 psycopg2==2.8.3
 pyjwt==1.7.1
 python-dateutil==2.8.0
@@ -55,7 +56,7 @@ pytz==2019.3
 pyyaml==5.1.2
 raven==6.10.0
 redis==3.3.11
-regex==2019.11.1
+regex==2020.7.14
 requests==2.22.0
 ruamel.yaml.clib==0.2.0
 ruamel.yaml==0.16.5
@@ -64,8 +65,9 @@ soupsieve==1.9.4
 sqlparse==0.3.0
 tblib==1.4.0
 text-unidecode==1.3
-toml==0.10.0
+toml==0.10.1
 typed-ast==1.4.0
+typing-extensions==3.7.4.3
 unidecode==1.1.1
 uritemplate==3.0.0
 urllib3==1.25.6
diff --git a/requirements/dev.txt b/requirements/dev.txt
index 35d8b88..6975c71 100644
--- a/requirements/dev.txt
+++ b/requirements/dev.txt
@@ -2,18 +2,18 @@
 # This file is autogenerated by pip-compile
 # To update, run:
 #
-#    pip-compile --no-index --output-file requirements/dev.txt requirements/base.txt requirements/dev.in requirements/testing.in
+#    pip-compile --no-index --output-file requirements/dev.txt requirements/base.txt requirements/testing.in requirements/dev.in
 #
 appdirs==1.4.3            # via black
-attrs==19.3.0             # via black
 beautifulsoup4==4.8.1     # via webtest
-black==19.10b0
+black==20.8b1
 certifi==2019.9.11
 chardet==3.0.4
-click==7.0
+click==7.1.2
 coreapi==2.3.3
 coreschema==0.0.4
 coverage==4.5.4
+dataclasses==0.6
 django-better-admin-arrayfield==1.0.4
 django-choices==1.7.0
 django-cors-middleware==1.4.0
@@ -43,9 +43,10 @@ itypes==1.1.0
 jinja2==2.10.3
 markdown==3.1.1
 markupsafe==1.1.1
+mypy-extensions==0.4.3    # via black
 oyaml==0.9
 pathspec==0.6.0           # via black
-pip-tools==4.2.0
+pip-tools==5.3.1
 psycopg2==2.8.3
 pyjwt==1.7.1
 python-dateutil==2.8.0
@@ -54,7 +55,7 @@ pytz==2019.3
 pyyaml==5.1.2
 raven==6.10.0
 redis==3.3.11
-regex==2019.11.1          # via black
+regex==2020.7.14          # via black
 requests==2.22.0
 ruamel.yaml.clib==0.2.0
 ruamel.yaml==0.16.5
@@ -63,8 +64,9 @@ soupsieve==1.9.4          # via beautifulsoup4
 sqlparse==0.3.0
 tblib==1.4.0
 text-unidecode==1.3       # via faker
-toml==0.10.0              # via black
+toml==0.10.1              # via black
 typed-ast==1.4.0          # via black
+typing-extensions==3.7.4.3  # via black
 unidecode==1.1.1
 uritemplate==3.0.0
 urllib3==1.25.6
diff --git a/requirements/testing.in b/requirements/testing.in
index 08426cb..61f474c 100644
--- a/requirements/testing.in
+++ b/requirements/testing.in
@@ -1,6 +1,7 @@
 # Shared between dev and jenkins requirements to run our tests
 black
 coverage
+dataclasses==0.6
 django-webtest
 factory_boy
 freezegun
diff --git a/src/verzoeken/accounts/migrations/0001_initial.py b/src/verzoeken/accounts/migrations/0001_initial.py
index 827dc3a..5d5b2c0 100644
--- a/src/verzoeken/accounts/migrations/0001_initial.py
+++ b/src/verzoeken/accounts/migrations/0001_initial.py
@@ -116,7 +116,12 @@ class Migration(migrations.Migration):
                     ),
                 ),
             ],
-            options={"verbose_name": "user", "verbose_name_plural": "users",},
-            managers=[("objects", verzoeken.accounts.managers.UserManager()),],
+            options={
+                "verbose_name": "user",
+                "verbose_name_plural": "users",
+            },
+            managers=[
+                ("objects", verzoeken.accounts.managers.UserManager()),
+            ],
         ),
     ]
diff --git a/src/verzoeken/api/serializers.py b/src/verzoeken/api/serializers.py
index 8842705..63f2e60 100644
--- a/src/verzoeken/api/serializers.py
+++ b/src/verzoeken/api/serializers.py
@@ -113,7 +113,9 @@ class Meta:
                 "lookup_field": "uuid",
                 "validators": [IsImmutableValidator()],
             },
-            "object": {"validators": [IsImmutableValidator()],},
+            "object": {
+                "validators": [IsImmutableValidator()],
+            },
             "object_type": {"validators": [IsImmutableValidator()]},
         }
         validators = [ObjectVerzoekCreateValidator()]
@@ -213,9 +215,15 @@ class Meta:
             "url": {"lookup_field": "uuid"},
             "verzoek": {
                 "lookup_field": "uuid",
-                "validators": [IsImmutableValidator(),],
+                "validators": [
+                    IsImmutableValidator(),
+                ],
+            },
+            "product": {
+                "validators": [
+                    IsImmutableValidator(),
+                ],
             },
-            "product": {"validators": [IsImmutableValidator(),],},
         }
 
     def validate(self, attrs):
@@ -238,7 +246,8 @@ class Meta:
         fields = ("url", "klant", "verzoek", "rol", "indicatie_machtiging")
         validators = [
             UniqueTogetherValidator(
-                queryset=KlantVerzoek.objects.all(), fields=["verzoek", "klant"],
+                queryset=KlantVerzoek.objects.all(),
+                fields=["verzoek", "klant"],
             ),
         ]
         extra_kwargs = {
diff --git a/src/verzoeken/api/tests/test_klantverzoek.py b/src/verzoeken/api/tests/test_klantverzoek.py
index 7c48696..16e505d 100644
--- a/src/verzoeken/api/tests/test_klantverzoek.py
+++ b/src/verzoeken/api/tests/test_klantverzoek.py
@@ -39,7 +39,9 @@ def test_list_filter_klantverzoek(self):
         self.assertEqual(len(data["results"]), 1)
 
         response = self.client.get(
-            list_url, {"klant": vc2.klant}, HTTP_HOST="testserver.com",
+            list_url,
+            {"klant": vc2.klant},
+            HTTP_HOST="testserver.com",
         )
         self.assertEqual(response.status_code, status.HTTP_200_OK)
 
diff --git a/src/verzoeken/api/tests/test_objectverzoek.py b/src/verzoeken/api/tests/test_objectverzoek.py
index ca7d632..f47fc51 100644
--- a/src/verzoeken/api/tests/test_objectverzoek.py
+++ b/src/verzoeken/api/tests/test_objectverzoek.py
@@ -51,9 +51,12 @@ def test_read_objectverzoek(self):
             },
         )
 
-    @override_settings(LINK_FETCHER="vng_api_common.mocks.link_fetcher_200",)
+    @override_settings(
+        LINK_FETCHER="vng_api_common.mocks.link_fetcher_200",
+    )
     @patch(
-        "zds_client.client.get_operation_url", return_value="/api/v1/zaakverzoeken",
+        "zds_client.client.get_operation_url",
+        return_value="/api/v1/zaakverzoeken",
     )
     @patch("zds_client.tests.mocks.MockClient.fetch_schema", return_value={})
     @patch("vng_api_common.validators.obj_has_shape", return_value=True)
@@ -86,9 +89,12 @@ def test_create_objectverzoek(self, *mocks):
         self.assertEqual(objectverzoek.object_type, ObjectTypes.zaak)
         self.assertEqual(objectverzoek.object, ZAAK)
 
-    @override_settings(LINK_FETCHER="vng_api_common.mocks.link_fetcher_200",)
+    @override_settings(
+        LINK_FETCHER="vng_api_common.mocks.link_fetcher_200",
+    )
     @patch(
-        "zds_client.client.get_operation_url", return_value="/api/v1/zaakverzoeken",
+        "zds_client.client.get_operation_url",
+        return_value="/api/v1/zaakverzoeken",
     )
     @patch("zds_client.tests.mocks.MockClient.fetch_schema", return_value={})
     @patch("vng_api_common.validators.obj_has_shape", return_value=True)
@@ -112,7 +118,8 @@ def test_create_objectverzoek_fail_no_remote_relation(self, *mocks):
         self.assertEqual(error["code"], "inconsistent-relation")
 
     @patch(
-        "zds_client.client.get_operation_url", return_value="/api/v1/zaakverzoeken",
+        "zds_client.client.get_operation_url",
+        return_value="/api/v1/zaakverzoeken",
     )
     @patch("zds_client.tests.mocks.MockClient.fetch_schema", return_value={})
     def test_destroy_objectverzoek(self, *mocks):
@@ -129,7 +136,8 @@ def test_destroy_objectverzoek(self, *mocks):
         self.assertEqual(ObjectVerzoek.objects.count(), 0)
 
     @patch(
-        "zds_client.client.get_operation_url", return_value="/api/v1/zaakverzoeken",
+        "zds_client.client.get_operation_url",
+        return_value="/api/v1/zaakverzoeken",
     )
     @patch("zds_client.tests.mocks.MockClient.fetch_schema", return_value={})
     def test_destroy_fail_existing_relation(self, *mocks):
diff --git a/src/verzoeken/api/tests/test_verzoekcontactmoment.py b/src/verzoeken/api/tests/test_verzoekcontactmoment.py
index e436066..1aa6afc 100644
--- a/src/verzoeken/api/tests/test_verzoekcontactmoment.py
+++ b/src/verzoeken/api/tests/test_verzoekcontactmoment.py
@@ -42,7 +42,9 @@ def test_list_filter_verzoekcontactmoment(self):
         self.assertEqual(len(data["results"]), 1)
 
         response = self.client.get(
-            list_url, {"contactmoment": vc2.contactmoment}, HTTP_HOST="testserver.com",
+            list_url,
+            {"contactmoment": vc2.contactmoment},
+            HTTP_HOST="testserver.com",
         )
         self.assertEqual(response.status_code, status.HTTP_200_OK)
 
diff --git a/src/verzoeken/datamodel/migrations/0004_auto_20200528_1324.py b/src/verzoeken/datamodel/migrations/0004_auto_20200528_1324.py
index bdf00f3..0979a9c 100644
--- a/src/verzoeken/datamodel/migrations/0004_auto_20200528_1324.py
+++ b/src/verzoeken/datamodel/migrations/0004_auto_20200528_1324.py
@@ -11,7 +11,10 @@ class Migration(migrations.Migration):
     ]
 
     operations = [
-        migrations.RemoveField(model_name="verzoek", name="klant",),
+        migrations.RemoveField(
+            model_name="verzoek",
+            name="klant",
+        ),
         migrations.AlterField(
             model_name="verzoek",
             name="registratiedatum",
diff --git a/src/verzoeken/datamodel/migrations/0005_auto_20200528_1628.py b/src/verzoeken/datamodel/migrations/0005_auto_20200528_1628.py
index b29e6ff..18f8f10 100644
--- a/src/verzoeken/datamodel/migrations/0005_auto_20200528_1628.py
+++ b/src/verzoeken/datamodel/migrations/0005_auto_20200528_1628.py
@@ -43,6 +43,7 @@ class Migration(migrations.Migration):
             ),
         ),
         migrations.AlterUniqueTogether(
-            name="klantverzoek", unique_together={("verzoek", "klant")},
+            name="klantverzoek",
+            unique_together={("verzoek", "klant")},
         ),
     ]
diff --git a/src/verzoeken/datamodel/models.py b/src/verzoeken/datamodel/models.py
index 40fe46a..ff8b34f 100644
--- a/src/verzoeken/datamodel/models.py
+++ b/src/verzoeken/datamodel/models.py
@@ -233,7 +233,8 @@ class KlantVerzoek(models.Model):
         help_text="URL-referentie naar het VERZOEK.",
     )
     klant = models.URLField(
-        max_length=1000, help_text=_("URL-referentie naar een KLANT (in Klanten API)"),
+        max_length=1000,
+        help_text=_("URL-referentie naar een KLANT (in Klanten API)"),
     )
     rol = models.CharField(
         max_length=100,
diff --git a/src/verzoeken/datamodel/tests/test_audittrail_unique_representation.py b/src/verzoeken/datamodel/tests/test_audittrail_unique_representation.py
index 9493606..3d627dd 100644
--- a/src/verzoeken/datamodel/tests/test_audittrail_unique_representation.py
+++ b/src/verzoeken/datamodel/tests/test_audittrail_unique_representation.py
@@ -35,7 +35,8 @@ def test_verzoekproduct(self):
     @override_settings(ZDS_CLIENT_CLASS="vng_api_common.mocks.MockClient")
     def test_verzoekinformatieobject(self):
         vio = VerzoekInformatieObjectFactory.create(
-            verzoek__bronorganisatie="154760924", verzoek__identificatie="12345",
+            verzoek__bronorganisatie="154760924",
+            verzoek__identificatie="12345",
         )
         responses = {
             vio.informatieobject: {