diff --git a/pyproject.toml b/pyproject.toml
index 03d2f1c..fbd7ac5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,5 +1,5 @@
 [build-system]
-requires = ["flit_core>=3.12.0,<4"]
+requires = ["flit_core>=3.12.0,<5"]
 build-backend = "flit_core.buildapi"
 
 [project]