diff --git a/exca/base.py b/exca/base.py
index 121c4bdd..bcbf0c12 100644
--- a/exca/base.py
+++ b/exca/base.py
@@ -44,6 +44,7 @@ def _add_name(
     obj: pydantic.BaseModel, propagate_defaults: bool = False
 ) -> pydantic.BaseModel:
     """Provide owner object to the infra"""
+
     private = obj.__pydantic_private__ or {}
     params = collections.ChainMap(dict(obj), private)
     for name, val in params.items():
@@ -84,10 +85,11 @@ def _add_name(
 
 
 @pydantic.model_validator(mode="before")
-def model_with_infra_validator_before(obj: tp.Any) -> tp.Any:
+def model_with_infra_validator_before(cls, obj: tp.Any) -> tp.Any:
     """Provide owner object to the infra
     (this is set to the owner class during __set_name__)
     """
+    utils.check_extra_forbid(cls)
     if not isinstance(obj, dict):
         return obj  # should not happen
     for name, val in obj.items():
@@ -149,6 +151,7 @@ def __set_name__(self, owner: tp.Type[pydantic.BaseModel], name: str) -> None:
             msg += f"{cls} must inherit from pydantic.BaseModel"
             raise RuntimeError(msg)
         owner.model_config.setdefault("extra", "forbid")
+        owner.model_config.setdefault("revalidate_instances", "always")
         self._infra_name = name
         # set mechanism to provide owner obj to the infra:
         owner._model_with_infra_validator_after = model_with_infra_validator_after  # type: ignore
diff --git a/exca/test_base.py b/exca/test_base.py
index 2477f946..37b1f3c8 100644
--- a/exca/test_base.py
+++ b/exca/test_base.py
@@ -406,6 +406,23 @@ def test_weird_types(tmp_path: Path) -> None:
     whatever.build()
 
 
+def test_recursive_model() -> None:
+    class SubData(pydantic.BaseModel):
+        x: int = 12
+
+    class Recursive(pydantic.BaseModel):
+        submodels: list["Recursive"] = []
+        subd: SubData = SubData()
+        infra: TaskInfra = TaskInfra()
+
+    r = Recursive(submodels=[{}, {}], subd={"y": 3})  # type: ignore
+    print("Here Cfg", SubData.model_config)
+    r = Recursive(submodels=[{}, {}], subd={"y": 3})  # type: ignore
+    # r.subd.y = 13
+    # print(r.subd.y)
+    raise
+
+
 def test_defined_in_main() -> None:
     try:
         import neuralset as ns
diff --git a/exca/utils.py b/exca/utils.py
index 07367c7c..c74e8ec4 100644
--- a/exca/utils.py
+++ b/exca/utils.py
@@ -363,6 +363,29 @@ def find_models(
     return out
 
 
+_CHECKED: list[tp.Type[pydantic.BaseModel]] = []
+
+
+def check_extra_forbid(cls: tp.Type[pydantic.BaseModel]) -> None:
+    if cls in _CHECKED:
+        return
+    _CHECKED.append(cls)
+    cfg = cls.model_config
+    if "extra" not in cfg:
+        msg = f"Automatically setting extra='forbid' for {cls.__name__} "
+        msg += "(bypass by explicitely setting: model_config = pydantic.ConfigDict(extra='forbid'))"
+        logging.debug(msg)
+        cfg["extra"] = "forbid"
+    for val in cls.model_fields.values():
+        for annot in _pydantic_hints(val.annotation):
+            try:
+                check_extra_forbid(annot)
+            except Exception as e:
+                raise ValueError(f"Failing for {val.annotation} ({annot=})") from e
+    # rebuilding only after subclasses were rebuilt
+    cls.model_rebuild(force=True)
+
+
 def _pydantic_hints(hint: tp.Any) -> tp.List[tp.Type[pydantic.BaseModel]]:
     """Checks if a type hint contains pydantic models"""
     try: