diff --git a/pyproject.toml b/pyproject.toml
index 0531d362..65dff67c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -3,7 +3,7 @@ name = "atomworks"
 version = "2.1.1"
 description = "A research-oriented data toolkit for training biomolecular deep-learning foundation models"
 readme = "README.md"
-requires-python = ">=3.11"
+requires-python = ">=3.11,<3.13"
 authors = [
     { name = "Institute for Protein Design", email = "contact@ipd.uw.edu" }
 ]