diff --git a/pyproject.toml b/pyproject.toml
index f9225954dff4b27498b2324134acaf9b4b2367a4..345808fa201968db6b19e01220891edc4c3f4ac8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -33,7 +33,7 @@ packages = [
 
 
 [tool.poetry.dependencies]
-python = ">=3.8"
+python = ">=3.8,<4.0"
 numpy  = ">= 1.12"