diff --git a/src/plaster/__init__.py b/src/plaster/__init__.py
index a1cffaf..595f9ec 100644
--- a/src/plaster/__init__.py
+++ b/src/plaster/__init__.py
@@ -1,7 +1,18 @@
 # public api
 # flake8: noqa
 
-from .exceptions import InvalidURI, LoaderNotFound, MultipleLoadersFound, PlasterError
+from .exceptions import (
+    InvalidURI,
+    LoaderNotFound,
+    MultipleLoadersFound,
+    PlasterError,
+)
 from .interfaces import ILoader, ILoaderFactory, ILoaderInfo
-from .loaders import find_loaders, get_loader, get_sections, get_settings, setup_logging
+from .loaders import (
+    find_loaders,
+    get_loader,
+    get_sections,
+    get_settings,
+    setup_logging,
+)
 from .uri import PlasterURL, parse_uri
diff --git a/src/plaster/exceptions.py b/src/plaster/exceptions.py
index 93a91bf..fda5080 100644
--- a/src/plaster/exceptions.py
+++ b/src/plaster/exceptions.py
@@ -61,7 +61,8 @@ def __init__(self, scheme, loaders, protocols=None, message=None):
             if protocols is not None:
                 scheme_msg += ', protocol "{}"'.format(", ".join(protocols))
             loader_list = ", ".join(
-                loader.scheme for loader in sorted(loaders, key=lambda v: v.scheme)
+                loader.scheme
+                for loader in sorted(loaders, key=lambda v: v.scheme)
             )
             message = (
                 "Multiple plaster loaders were found for {}. "
diff --git a/src/plaster/loaders.py b/src/plaster/loaders.py
index f7b10d1..5a2df7b 100644
--- a/src/plaster/loaders.py
+++ b/src/plaster/loaders.py
@@ -141,7 +141,9 @@ def find_loaders(scheme, protocols=None):
     matching_groups = ["plaster.loader_factory"]
 
     if protocols:
-        matching_groups += [f"plaster.{proto}_loader_factory" for proto in protocols]
+        matching_groups += [
+            f"plaster.{proto}_loader_factory" for proto in protocols
+        ]
     scheme = scheme.lower()
 
     # if a distribution is specified then it overrides the default search
@@ -203,7 +205,8 @@ class EntryPointLoaderInfo(ILoaderInfo):
     def __init__(self, dist, ep, protocols=None):
         self.entry_point = ep
         self.scheme = "{}+{}".format(
-            dist.metadata["name"] if "name" in dist.metadata else "Unknown", ep.name
+            dist.metadata["name"] if "name" in dist.metadata else "Unknown",
+            ep.name,
         )
         self.protocols = protocols
 
diff --git a/src/plaster/uri.py b/src/plaster/uri.py
index 2c4dafb..2eab411 100644
--- a/src/plaster/uri.py
+++ b/src/plaster/uri.py
@@ -130,4 +130,6 @@ def parse_uri(config_uri):
             ),
         )
 
-    return PlasterURL(scheme=scheme, path=path, options=options, fragment=fragment)
+    return PlasterURL(
+        scheme=scheme, path=path, options=options, fragment=fragment
+    )
diff --git a/tests/test_exceptions.py b/tests/test_exceptions.py
index fdfb3be..8cedf24 100644
--- a/tests/test_exceptions.py
+++ b/tests/test_exceptions.py
@@ -28,7 +28,9 @@ def test_it(self):
         assert isinstance(exc, ValueError)
         assert exc.scheme == "foo"
         assert exc.protocols is None
-        assert exc.message == ('Could not find a matching loader for the scheme "foo".')
+        assert exc.message == (
+            'Could not find a matching loader for the scheme "foo".'
+        )
 
     def test_it_with_protocol(self):
         exc = self._makeOne("foo", ["wsgi"])
@@ -36,7 +38,8 @@ def test_it_with_protocol(self):
         assert exc.scheme == "foo"
         assert exc.protocols == ["wsgi"]
         assert exc.message == (
-            'Could not find a matching loader for the scheme "foo", ' 'protocol "wsgi".'
+            'Could not find a matching loader for the scheme "foo", '
+            'protocol "wsgi".'
         )
 
     def test_it_with_multiple_protocols(self):
@@ -94,7 +97,9 @@ def test_it_with_protocol(self):
     def test_it_with_multiple_protocols(self):
         dummy1 = DummyLoaderInfo("dummy1")
         dummy2 = DummyLoaderInfo("dummy2")
-        exc = self._makeOne("https", [dummy1, dummy2], protocols=["wsgi", "qt"])
+        exc = self._makeOne(
+            "https", [dummy1, dummy2], protocols=["wsgi", "qt"]
+        )
         assert isinstance(exc, ValueError)
         assert exc.message == (
             'Multiple plaster loaders were found for scheme "https", '
diff --git a/tox.ini b/tox.ini
index 10534d4..63b04eb 100644
--- a/tox.ini
+++ b/tox.ini
@@ -33,8 +33,8 @@ extras =
 [testenv:lint]
 skip_install = True
 commands =
-    isort --check-only --df src/plaster tests
-    black --check --diff .
+    isort --check-only --line-length 79 --df src/plaster tests
+    black --check --diff --line-length 79 .
     flake8 src/plaster tests
     check-manifest
     # build sdist/wheel