diff --git a/jsonschema/tests/test_validators.py b/jsonschema/tests/test_validators.py
index fb59b83..8380de1 100644
--- a/jsonschema/tests/test_validators.py
+++ b/jsonschema/tests/test_validators.py
@@ -196,7 +196,7 @@ class TestValidationErrorMessages(unittest.TestCase):
                   u"additionalProperties": False,
                   u"patternProperties": {
                       u"^abc$": {u"type": u"string"},
-                      u"^def$": {u"type": u"string"}
+                      u"^def$": {u"type": u"string"},
                   }}
         message = self.message_for({u"zebra": 123}, schema,
                                    cls=Draft4Validator)
diff --git a/jsonschema/validators.py b/jsonschema/validators.py
index ee1ec94..0300760 100644
--- a/jsonschema/validators.py
+++ b/jsonschema/validators.py
@@ -14,9 +14,14 @@ from jsonschema.compat import (
     Sequence, urljoin, urlsplit, urldefrag, unquote, urlopen,
     str_types, int_types, iteritems, lru_cache,
 )
-from jsonschema.exceptions import ErrorTree  # Backwards compat  # noqa: F401
 from jsonschema.exceptions import RefResolutionError, SchemaError, UnknownType
 
+# Sigh. https://gitlab.com/pycqa/flake8/issues/280
+#       https://github.com/pyga/ebb-lint/issues/7
+# Imported for backwards compatibility.
+from jsonschema.exceptions import ErrorTree
+ErrorTree
+
 
 _unset = _utils.Unset()
 
diff --git a/tox.ini b/tox.ini
index c55a167..181a8e4 100644
--- a/tox.ini
+++ b/tox.ini
@@ -55,9 +55,8 @@ commands =
 
 [testenv:style]
 basepython = pypy
-deps = flake8
-commands =
-    flake8 [] --max-complexity 10 {toxinidir}/jsonschema
+deps = ebb-lint
+commands = flake8 {posargs} --max-complexity 10 {toxinidir}/jsonschema
 
 
 [flake8]