diff --git a/pyproject.toml b/pyproject.toml
index 59b98c5c..9eb53407 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -52,7 +52,7 @@ validate_models = [
     "planet[test]",
     # Pinned exactly: the drift check byte-compares regenerated output, so a
     # codegen release that changes formatting would fail it and block a release.
-    "datamodel-code-generator[http]==0.79.0",
+    "datamodel-code-generator[http]==0.81.0",
 ]
 lint = [
     "flake8",