diff --git a/examples/test/invalid_attributes.py b/examples/test/invalid_attributes.py
index 0f407fb..8984d0d 100644
--- a/examples/test/invalid_attributes.py
+++ b/examples/test/invalid_attributes.py
@@ -8,6 +8,10 @@
         a="Wrong",
         title="ok",
         another_wrong="wrong attr",
+        made="up",
+        clickable="clicked",
+        __properties=["made"],
+        __events=["clickable"],
     ).html
 )
 
diff --git a/src/trame_client/widgets/core.py b/src/trame_client/widgets/core.py
index dc81cee..6c6b7d8 100644
--- a/src/trame_client/widgets/core.py
+++ b/src/trame_client/widgets/core.py
@@ -427,7 +427,7 @@ def __init__(
 
         self._attributes = {}
         self._py_attr = kwargs
-        self._used_py_attr = {"trame_server"}
+        self._used_py_attr = {"trame_server", "__properties", "__events"}
         self._children = []
 
         # Handle raw attributes if provided