diff --git a/pyproject.toml b/pyproject.toml
index 498f4ac..7ba999a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -79,7 +79,7 @@ pytest = "^9.0.0"
 pytest-cov = "^7.0.0"
 pytest-asyncio = "^1.3.0"
 black = ">=24,<27"
-isort = "^5.0.0"
+isort = ">=5,<9"
 ruff = "^0.14.0"
 mypy = "^1.5.0"
 types-python-dateutil = "^2.8.0"