diff --git a/requirements.txt b/requirements.txt
index 50eed6ad60e..36d9958ecef 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -15,7 +15,7 @@
 
 # formatter
 black
-isort>=4.2.5,<5 # pylint==2.5.3 constraints isort [required: >=4.2.5,<5, installed: 4.3.21]
+isort>=4.2.5,<6 # pylint==2.5.3 constraints isort [required: >=4.2.5,<5, installed: 4.3.21]
 # dependency manager
 pip-tools
 # version manager