diff --git a/pyproject.toml b/pyproject.toml
index c386561..445e962 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -75,7 +75,7 @@ develop = [
   "poethepoet<1",
   "pyproject-fmt<2.3",
   "ruff<0.6",
-  "validate-pyproject<0.19",
+  "validate-pyproject<0.21",
 ]
 release = [
   "build<2",