diff --git a/pyproject.toml b/pyproject.toml
index bc402bb..187f26a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,5 +1,5 @@
 [build-system]
-requires = [ "flit-core<4,>=3.2",]
+requires = [ 'flit-core<5,>=3.2; python_version >= "3.10"', 'flit-core<4,>=3.2; python_version < "3.10"',]
 build-backend = "flit_core.buildapi"
 
 [project]
diff --git a/tox.ini b/tox.ini
index 2ce2515..c2a9b7a 100644
--- a/tox.ini
+++ b/tox.ini
@@ -3,6 +3,10 @@
 #     * tox
 #     * envlists
 #     * testenv:.package
+#     * testenv:py315-dev
+#     * testenv:py315
+#     * testenv:py314-dev
+#     * testenv:py314
 #     * testenv:py313-dev
 #     * testenv:py313
 #     * testenv:py312-dev