diff --git a/pyproject.toml b/pyproject.toml
index ec1a3689..7cf3e60d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [build-system]
 build-backend = "flit_core.buildapi"
-requires = ["flit_core>=3,<4"]
+requires = ["flit_core>=4,<5"]
 
 [project]
 authors = [{ name = "Delgan", email = "delgan.py@gmail.com" }]