diff --git a/hugr-py/pyproject.toml b/hugr-py/pyproject.toml
index f9e0282d9..88383735b 100644
--- a/hugr-py/pyproject.toml
+++ b/hugr-py/pyproject.toml
@@ -26,7 +26,7 @@ classifiers = [
 ]
 
 dependencies = [
-    "pydantic>=2.8,<2.9",
+    "pydantic>=2.8,<2.10",
     "pydantic-extra-types>=2.9.0",
     "semver>=3.0.2",
     "graphviz>=0.20.3",