diff --git a/drf_spectacular/contrib/django_oauth_toolkit.py b/drf_spectacular/contrib/django_oauth_toolkit.py
index 25985aaf..58486ef8 100644
--- a/drf_spectacular/contrib/django_oauth_toolkit.py
+++ b/drf_spectacular/contrib/django_oauth_toolkit.py
@@ -6,11 +6,12 @@ class DjangoOAuthToolkitScheme(OpenApiAuthenticationExtension):
     name = 'oauth2'
 
     def get_security_requirement(self, auto_schema):
-        from oauth2_provider.contrib.rest_framework import (
-            TokenHasScope, TokenMatchesOASRequirements, IsAuthenticatedOrTokenHasScope
-        )
         # TODO generalize (will also be used in versioning)
         from collections import namedtuple
+
+        from oauth2_provider.contrib.rest_framework import (
+            IsAuthenticatedOrTokenHasScope, TokenHasScope, TokenMatchesOASRequirements,
+        )
         Request = namedtuple('Request', ['method'])
 
         view = auto_schema.view
@@ -26,9 +27,10 @@ def get_security_requirement(self, auto_schema):
                 return {self.name: permission.get_scopes(request, view)}
 
     def get_security_definition(self, auto_schema):
-        from drf_spectacular.settings import spectacular_settings
         from oauth2_provider.settings import oauth2_settings
 
+        from drf_spectacular.settings import spectacular_settings
+
         flows = {}
         for flow_type in spectacular_settings.OAUTH2_FLOWS:
             flows[flow_type] = {}
diff --git a/drf_spectacular/contrib/rest_framework_simplejwt.py b/drf_spectacular/contrib/rest_framework_simplejwt.py
index deb266f8..caf399ed 100644
--- a/drf_spectacular/contrib/rest_framework_simplejwt.py
+++ b/drf_spectacular/contrib/rest_framework_simplejwt.py
@@ -7,6 +7,7 @@ class SimpleJWTScheme(OpenApiAuthenticationExtension):
 
     def get_security_definition(self, auto_schema):
         from rest_framework_simplejwt.settings import api_settings
+
         from drf_spectacular.plumbing import warn
 
         if len(api_settings.AUTH_HEADER_TYPES) > 1:
diff --git a/drf_spectacular/plumbing.py b/drf_spectacular/plumbing.py
index 58ed2730..2b6f7116 100644
--- a/drf_spectacular/plumbing.py
+++ b/drf_spectacular/plumbing.py
@@ -135,7 +135,7 @@ def get_lib_doc_excludes():
     # do not import on package level due to potential import recursion when loading
     # extensions as recommended:  USER's settings.py -> USER EXTENSIONS -> extensions.py
     # -> plumbing.py -> DRF views -> DRF DefaultSchema -> openapi.py - plumbing.py -> Loop
-    from rest_framework import generics, viewsets, views
+    from rest_framework import generics, views, viewsets
     return [
         views.APIView,
         *[getattr(serializers, c) for c in dir(serializers) if c.endswith('Serializer')],
diff --git a/requirements/testing.txt b/requirements/testing.txt
index 53f9a073..17f104b7 100644
--- a/requirements/testing.txt
+++ b/requirements/testing.txt
@@ -4,4 +4,4 @@ pytest-cov>=2.8.1
 flake8>=3.7.9
 mypy>=0.770
 djangorestframework-stubs>=1.1.0
-isort>=4.3.21
\ No newline at end of file
+isort>=5.0.4
\ No newline at end of file
diff --git a/runtests.py b/runtests.py
index 84b8a52b..2e2cd512 100755
--- a/runtests.py
+++ b/runtests.py
@@ -16,7 +16,7 @@
 
 MYPY_ARGS = ['--config-file=tox.ini', 'drf_spectacular']
 
-ISORT_ARGS = ['--check', '-df']
+ISORT_ARGS = ['--check', '--diff', '.']
 
 sys.path.append(os.path.dirname(__file__))
 
@@ -43,7 +43,7 @@ def mypy_main(args):
 def isort_main(args):
     print('Running isort code linting')
     ret = subprocess.call(['isort'] + args)
-    print('isort failed, run: isort -rc .' if ret else 'isort passed')
+    print('isort failed, run: isort --interactive .' if ret else 'isort passed')
     return ret
 
 
diff --git a/tests/__init__.py b/tests/__init__.py
index aa45988a..571a6350 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -2,7 +2,7 @@
 
 
 def assert_schema(schema, reference_file):
-    from drf_spectacular.renderers import OpenApiYamlRenderer, OpenApiJsonRenderer
+    from drf_spectacular.renderers import OpenApiJsonRenderer, OpenApiYamlRenderer
 
     schema_yml = OpenApiYamlRenderer().render(schema, renderer_context={})
     # render also a json and provoke serialization issues
@@ -22,6 +22,7 @@ def generate_schema(route, viewset=None, view=None, view_function=None):
     from django.urls import path
     from rest_framework import routers
     from rest_framework.viewsets import ViewSetMixin
+
     from drf_spectacular.generators import SchemaGenerator
 
     patterns = []
diff --git a/tests/contrib/test_oauth_toolkit.py b/tests/contrib/test_oauth_toolkit.py
index a757f45d..bc2bc75c 100644
--- a/tests/contrib/test_oauth_toolkit.py
+++ b/tests/contrib/test_oauth_toolkit.py
@@ -10,8 +10,8 @@
 
 try:
     from oauth2_provider.contrib.rest_framework import (
-        IsAuthenticatedOrTokenHasScope, OAuth2Authentication,
-        TokenHasReadWriteScope, TokenHasResourceScope,
+        IsAuthenticatedOrTokenHasScope, OAuth2Authentication, TokenHasReadWriteScope,
+        TokenHasResourceScope,
     )
 except ImportError:
     IsAuthenticatedOrTokenHasScope = None
diff --git a/tests/test_warnings.py b/tests/test_warnings.py
index 519e6c2e..f71d7fe2 100644
--- a/tests/test_warnings.py
+++ b/tests/test_warnings.py
@@ -10,6 +10,7 @@
 
 def test_serializer_name_reuse(warnings):
     from rest_framework import routers
+
     from drf_spectacular.generators import SchemaGenerator
     router = routers.SimpleRouter()