diff --git a/pyproject.toml b/pyproject.toml
index 35c7bb7..41ea352 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -3,7 +3,7 @@
 # SPDX-License-Identifier: CC0-1.0 OR MIT OR Unlicense
 
 [build-system]
-requires = ["flit_core ~=3.2"]
+requires = ["flit_core >=3.2,<5.0"]
 build-backend = "flit_core.buildapi"
 
 [project]