diff --git a/pyproject.toml b/pyproject.toml
index b92a8aa..670a09a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,7 @@
 [build-system]
 #requires = ["setuptools", "setuptools-scm"]
 #build-backend = "setuptools.build_meta"
-requires = ["flit_core >=3.2,<4"]
+requires = ["flit_core >=3.2,<5"]
 build-backend = "flit_core.buildapi"
 
 [tool.setuptools]