diff --git a/runtests.py b/runtests.py
index 1627e33b2..31593c3b4 100755
--- a/runtests.py
+++ b/runtests.py
@@ -14,7 +14,7 @@ PYTEST_ARGS = {
 
 FLAKE8_ARGS = ['rest_framework', 'tests', '--ignore=E501']
 
-ISORT_ARGS = ['--recursive', '--check-only', '-p', 'tests', 'rest_framework', 'tests']
+ISORT_ARGS = ['--recursive', '--diff', '-p', 'tests', 'rest_framework', 'tests']
 
 sys.path.append(os.path.dirname(__file__))