diff --git a/pyproject.toml b/pyproject.toml
index bdeea9f..564120b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,6 +4,7 @@ build-backend = "flit_core.buildapi"
 
 [project]
 name = "topojson"
+requires-python = ">=3.8"
 dynamic = ["version", "description"]
 authors = [
     {name = "Mattijn van Hoek", email = "mattijn@gmail.com"},