diff --git a/pyproject.toml b/pyproject.toml
index d9c6661..8a29de3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -3,7 +3,7 @@ name = "icebug-format"
 version = "0.1.0"
 description = "Convert graph data from non-CSR formats to the icebug format (CSR)."
 readme = "README.md"
-requires-python = ">=3.13"
+requires-python = ">=3.9"
 dependencies = [
     "duckdb>=1.3.2",
     "pyarrow>=21.0.0",