diff --git a/src/_zkapauthorizer/_storage_server.py b/src/_zkapauthorizer/_storage_server.py
index 2d774aca410ebe7e9eb507d8ed3f14d34809c4f4..f81f75bd1ad4dc97b30b70986d3effcf97ce15d9 100644
--- a/src/_zkapauthorizer/_storage_server.py
+++ b/src/_zkapauthorizer/_storage_server.py
@@ -27,8 +27,31 @@ from __future__ import print_function
 from __future__ import unicode_literals
 
 from future.utils import PY2
+
 if PY2:
-    from future.builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, str, max, min  # noqa: F401
+    from future.builtins import (
+        filter,
+        map,
+        zip,
+        ascii,
+        chr,
+        hex,
+        input,
+        next,
+        oct,
+        open,
+        pow,
+        round,
+        super,
+        bytes,
+        dict,
+        list,
+        object,
+        range,
+        str,
+        max,
+        min,
+    )  # noqa: F401
 
 from datetime import timedelta
 from errno import ENOENT
diff --git a/src/_zkapauthorizer/eliot.py b/src/_zkapauthorizer/eliot.py
index ccd847276fbc90a5c055b34979011c8076e20443..2adc410b6051b829a50ab5358900848668f51ee0 100644
--- a/src/_zkapauthorizer/eliot.py
+++ b/src/_zkapauthorizer/eliot.py
@@ -22,8 +22,31 @@ from __future__ import print_function
 from __future__ import unicode_literals
 
 from future.utils import PY2
+
 if PY2:
-    from future.builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, str, max, min  # noqa: F401
+    from future.builtins import (
+        filter,
+        map,
+        zip,
+        ascii,
+        chr,
+        hex,
+        input,
+        next,
+        oct,
+        open,
+        pow,
+        round,
+        super,
+        bytes,
+        dict,
+        list,
+        object,
+        range,
+        str,
+        max,
+        min,
+    )  # noqa: F401
 
 from eliot import ActionType, Field, MessageType
 
diff --git a/src/_zkapauthorizer/model.py b/src/_zkapauthorizer/model.py
index 57b7cb4aa8f63c8264d1ab7ff23f830c8ceb5469..14306b15e2df5a1513197351d578b65911fd404e 100644
--- a/src/_zkapauthorizer/model.py
+++ b/src/_zkapauthorizer/model.py
@@ -23,8 +23,31 @@ from __future__ import print_function
 from __future__ import unicode_literals
 
 from future.utils import PY2
+
 if PY2:
-    from future.builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, str, max, min  # noqa: F401
+    from future.builtins import (
+        filter,
+        map,
+        zip,
+        ascii,
+        chr,
+        hex,
+        input,
+        next,
+        oct,
+        open,
+        pow,
+        round,
+        super,
+        bytes,
+        dict,
+        list,
+        object,
+        range,
+        str,
+        max,
+        min,
+    )  # noqa: F401
 from past.builtins import long
 
 from datetime import datetime
diff --git a/src/_zkapauthorizer/resource.py b/src/_zkapauthorizer/resource.py
index 89b0a11fb26e21cb623c22a4f14a51826cb73c96..9436b19102d4e3d2c4b500b6a8db680e468c562e 100644
--- a/src/_zkapauthorizer/resource.py
+++ b/src/_zkapauthorizer/resource.py
@@ -27,8 +27,31 @@ from __future__ import print_function
 from __future__ import unicode_literals
 
 from future.utils import PY2
+
 if PY2:
-    from future.builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, str, max, min  # noqa: F401
+    from future.builtins import (
+        filter,
+        map,
+        zip,
+        ascii,
+        chr,
+        hex,
+        input,
+        next,
+        oct,
+        open,
+        pow,
+        round,
+        super,
+        bytes,
+        dict,
+        list,
+        object,
+        range,
+        str,
+        max,
+        min,
+    )  # noqa: F401
 from past.builtins import long
 
 from itertools import islice
diff --git a/src/_zkapauthorizer/storage_common.py b/src/_zkapauthorizer/storage_common.py
index aeb861841946a05a2448937712ee030b4270c2f2..4239ee552014107348cf5ec6d95b6455d46931a0 100644
--- a/src/_zkapauthorizer/storage_common.py
+++ b/src/_zkapauthorizer/storage_common.py
@@ -22,8 +22,31 @@ from __future__ import print_function
 from __future__ import unicode_literals
 
 from future.utils import PY2
+
 if PY2:
-    from future.builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, str, max, min  # noqa: F401
+    from future.builtins import (
+        filter,
+        map,
+        zip,
+        ascii,
+        chr,
+        hex,
+        input,
+        next,
+        oct,
+        open,
+        pow,
+        round,
+        super,
+        bytes,
+        dict,
+        list,
+        object,
+        range,
+        str,
+        max,
+        min,
+    )  # noqa: F401
 from past.builtins import long
 
 from base64 import b64encode
@@ -146,6 +169,7 @@ def get_configured_allowed_public_keys(node_config):
 
 _dict_values = type(dict().values())
 
+
 def required_passes(bytes_per_pass, share_sizes):
     """
     Calculate the number of passes that are required to store shares of the
diff --git a/src/_zkapauthorizer/tests/strategies.py b/src/_zkapauthorizer/tests/strategies.py
index 6ce17b9381921e08ea0805991ab247d0baca6053..1b6528cdc54a2af5571d3b9ab106c6cbe1f3c862 100644
--- a/src/_zkapauthorizer/tests/strategies.py
+++ b/src/_zkapauthorizer/tests/strategies.py
@@ -22,8 +22,31 @@ from __future__ import print_function
 from __future__ import unicode_literals
 
 from future.utils import PY2
+
 if PY2:
-    from future.builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, str, max, min  # noqa: F401
+    from future.builtins import (
+        filter,
+        map,
+        zip,
+        ascii,
+        chr,
+        hex,
+        input,
+        next,
+        oct,
+        open,
+        pow,
+        round,
+        super,
+        bytes,
+        dict,
+        list,
+        object,
+        range,
+        str,
+        max,
+        min,
+    )  # noqa: F401
 
 from base64 import b64encode, urlsafe_b64encode
 from datetime import datetime, timedelta
@@ -258,7 +281,7 @@ def server_configurations(signing_key_path):
             {
                 "pass-value":
                 # The configuration is ini so everything is always a byte string!
-                integers(min_value=1).map(lambda v: u"{}".format(v).encode("ascii")),
+                integers(min_value=1).map(lambda v: "{}".format(v).encode("ascii")),
             }
         ),
         just({}),
diff --git a/src/_zkapauthorizer/tests/test_client_resource.py b/src/_zkapauthorizer/tests/test_client_resource.py
index 26f0786a9f11efdc7d156141284459d60f6ccc86..6b0d677f23acf877931352156282ae2d4fd48554 100644
--- a/src/_zkapauthorizer/tests/test_client_resource.py
+++ b/src/_zkapauthorizer/tests/test_client_resource.py
@@ -23,8 +23,31 @@ from __future__ import print_function
 from __future__ import unicode_literals
 
 from future.utils import PY2
+
 if PY2:
-    from future.builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, str, max, min  # noqa: F401
+    from future.builtins import (
+        filter,
+        map,
+        zip,
+        ascii,
+        chr,
+        hex,
+        input,
+        next,
+        oct,
+        open,
+        pow,
+        round,
+        super,
+        bytes,
+        dict,
+        list,
+        object,
+        range,
+        str,
+        max,
+        min,
+    )  # noqa: F401
 
 from datetime import datetime
 from io import BytesIO
diff --git a/src/_zkapauthorizer/tests/test_controller.py b/src/_zkapauthorizer/tests/test_controller.py
index 1dc17948d60620eedc151506d8937610d9d715ec..fa15e3cc8bb061308707949295ac2948037cb525 100644
--- a/src/_zkapauthorizer/tests/test_controller.py
+++ b/src/_zkapauthorizer/tests/test_controller.py
@@ -1297,6 +1297,7 @@ class BracketTests(TestCase):
     """
     Tests for ``bracket``.
     """
+
     def test_success(self):
         """
         ``bracket`` calls ``first`` then ``between`` then ``last`` and returns a
@@ -1305,9 +1306,11 @@ class BracketTests(TestCase):
         result = object()
         actions = []
         first = partial(actions.append, "first")
+
         def between():
             actions.append("between")
             return result
+
         last = partial(actions.append, "last")
         self.assertThat(
             bracket(first, last, between),
@@ -1325,13 +1328,17 @@ class BracketTests(TestCase):
         ``bracket`` calls ``first`` then ``between`` then ``last`` and returns a
         ``Deferred`` that fires with the failure result of ``between``.
         """
+
         class SomeException(Exception):
             pass
+
         actions = []
         first = partial(actions.append, "first")
+
         def between():
             actions.append("between")
             raise SomeException()
+
         last = partial(actions.append, "last")
         self.assertThat(
             bracket(first, last, between),
diff --git a/src/_zkapauthorizer/tests/test_plugin.py b/src/_zkapauthorizer/tests/test_plugin.py
index 56c63aa6f41b28b336d5410b95ee3946496f871c..10f25b436e82dc7766dc81fe67c0c96097203857 100644
--- a/src/_zkapauthorizer/tests/test_plugin.py
+++ b/src/_zkapauthorizer/tests/test_plugin.py
@@ -22,8 +22,31 @@ from __future__ import print_function
 from __future__ import unicode_literals
 
 from future.utils import PY2
+
 if PY2:
-    from future.builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, str, max, min  # noqa: F401
+    from future.builtins import (
+        filter,
+        map,
+        zip,
+        ascii,
+        chr,
+        hex,
+        input,
+        next,
+        oct,
+        open,
+        pow,
+        round,
+        super,
+        bytes,
+        dict,
+        list,
+        object,
+        range,
+        str,
+        max,
+        min,
+    )  # noqa: F401
 
 from datetime import timedelta
 from functools import partial
diff --git a/src/_zkapauthorizer/tests/test_pricecalculator.py b/src/_zkapauthorizer/tests/test_pricecalculator.py
index 2dd7ab918fbe0ca2736b62a73e92405cfcf38df3..b2b396978d599256bb03d346be80f07fafd5a113 100644
--- a/src/_zkapauthorizer/tests/test_pricecalculator.py
+++ b/src/_zkapauthorizer/tests/test_pricecalculator.py
@@ -23,8 +23,31 @@ from __future__ import print_function
 from __future__ import unicode_literals
 
 from future.utils import PY2
+
 if PY2:
-    from future.builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, str, max, min  # noqa: F401
+    from future.builtins import (
+        filter,
+        map,
+        zip,
+        ascii,
+        chr,
+        hex,
+        input,
+        next,
+        oct,
+        open,
+        pow,
+        round,
+        super,
+        bytes,
+        dict,
+        list,
+        object,
+        range,
+        str,
+        max,
+        min,
+    )  # noqa: F401
 from past.builtins import long
 
 from functools import partial