diff --git a/requirements-dev.txt b/requirements-dev.txt
index e98055d..e4676a6 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,6 +1,6 @@
 -e .
 coverage==4.4.1
-isort==4.2.5
+isort==4.2.9
 py==1.4.33
 pytest==3.1.0
 pytest-django==3.1.2
diff --git a/tests/models.py b/tests/models.py
index 6c92a51..ee0f6ac 100644
--- a/tests/models.py
+++ b/tests/models.py
@@ -8,9 +8,10 @@
 
 from stdimage import StdImageField
 from stdimage.models import StdImageFieldFile
-from stdimage.utils import (UploadTo, UploadToAutoSlugClassNameDir,
-                            UploadToUUID, pre_delete_delete_callback,
-                            pre_save_delete_callback, render_variations)
+from stdimage.utils import (
+    UploadTo, UploadToAutoSlugClassNameDir, UploadToUUID,
+    pre_delete_delete_callback, pre_save_delete_callback, render_variations
+)
 from stdimage.validators import MaxSizeValidator, MinSizeValidator