diff --git a/setup.py b/setup.py
index 39f17ba..eafc2e4 100644
--- a/setup.py
+++ b/setup.py
@@ -84,7 +84,7 @@ def read(path):
         devel=[
             'coverage<8',
             'flake8<8',
-            'isort<8',
+            'isort<9',
         ],
         argcompletion=['argcomplete']
     ),