diff --git a/test-requirements.txt b/test-requirements.txt
index 737b13de38..d96b9b8571 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -13,6 +13,7 @@ astroid==2.1.0 # LGPLv2.1
 bandit!=1.6.0,>=1.4.0 # Apache-2.0
 coverage!=4.4,>=4.0 # Apache-2.0
 flake8-import-order==0.12 # LGPLv3
+isort<5 # MIT
 nodeenv>=0.9.4 # BSD
 pytest>=5.3.5 # MIT
 pytest-django>=3.8.0 # BSD (3 clause)