diff --git a/pyproject.toml b/pyproject.toml
index 624b42e7..a7803947 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -58,10 +58,10 @@ test = [
 ]
 check = [
     "mypy>=0.990",
-    "flake8<6",
+    "flake8>=6.0.0,<7.0.0",
     "flake8-black",
     "flake8-colors",
-    "flake8-isort>=5.0.3,<6.0.0",
+    "flake8-isort>=6.0.0,<7.0.0",
     "flake8-pyi",
     "flake8-typing-imports",
     "docutils",