diff --git a/pyproject.toml b/pyproject.toml
index 4bb3103..72e9389 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -18,7 +18,7 @@ bump2version = "^1.0.0"
 pre-commit = "^4.0.1"
 pylint = ">=3.3,<5.0"
 yamllint = "^1.35.0"
-isort = "^6.0.1"
+isort = ">=6.0.1,<9.0.0"
 toml = "^0.10.0"
 black = ">=25.1,<27.0"
 pytest = "^8.3.1"