diff --git a/pyproject.toml b/pyproject.toml
index d18a049..085fabb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -107,7 +107,7 @@ develop = [
   "pyproject-fmt<2.3",
   "ruff<0.6",
   "sphinx-autobuild==2021.3.14", # Newer versions stopped "watching" appropriately?
-  "validate-pyproject<0.19",
+  "validate-pyproject<0.20",
 ]
 docs = [
   "furo",