diff --git a/.isort.cfg b/.isort.cfg
index bd5648e08f..4d4a6a509d 100644
--- a/.isort.cfg
+++ b/.isort.cfg
@@ -2,5 +2,6 @@
 skip=.tox
 atomic=true
 multi_line_output=5
+known_standard_library=types
 known_third_party=pytest,django
 known_first_party=rest_framework
diff --git a/requirements/requirements-codestyle.txt b/requirements/requirements-codestyle.txt
index 1412a4d861..2284a4cab6 100644
--- a/requirements/requirements-codestyle.txt
+++ b/requirements/requirements-codestyle.txt
@@ -3,4 +3,4 @@ flake8==2.4.0
 pep8==1.5.7
 
 # Sort and lint imports
-isort==3.9.6
+isort==4.2.2
diff --git a/requirements/requirements-packaging.txt b/requirements/requirements-packaging.txt
index 7510dbd795..8f62ee3657 100644
--- a/requirements/requirements-packaging.txt
+++ b/requirements/requirements-packaging.txt
@@ -5,4 +5,4 @@ wheel==0.24.0
 twine==1.4.0
 
 # Transifex client for managing translation resources.
-transifex-client==0.11b3
+transifex-client==0.11
diff --git a/rest_framework/utils/representation.py b/rest_framework/utils/representation.py
index 9207517193..49f829c102 100644
--- a/rest_framework/utils/representation.py
+++ b/rest_framework/utils/representation.py
@@ -40,7 +40,7 @@ def smart_repr(value):
     # <django.core.validators.RegexValidator object at 0x1047af050>
     # Should be presented as
     # <django.core.validators.RegexValidator object>
-    value = re.sub(' at 0x[0-9a-f]{4,32}>', '>', value)
+    value = re.sub(' at 0x[0-9A-Fa-f]{4,32}>', '>', value)
 
     return value