diff --git a/src/apify/_actor.py b/src/apify/_actor.py
index e00e4663..20242a9a 100644
--- a/src/apify/_actor.py
+++ b/src/apify/_actor.py
@@ -4,6 +4,7 @@
 import sys
 import warnings
 from contextlib import suppress
+from dataclasses import asdict
 from datetime import UTC, datetime, timedelta
 from functools import cached_property
 from typing import TYPE_CHECKING, Any, Literal, TypeVar, cast, overload
@@ -1283,15 +1284,16 @@ async def add_webhook(self, webhook: Webhook, *, idempotency_key: str | None = N
         if not self.configuration.actor_run_id:
             raise RuntimeError('actor_run_id cannot be None when running on the Apify platform.')
 
+        # `Webhook`'s field names match `webhooks().create()`'s parameters, so we forward them by name rather
+        # than listing each one.
+        webhook_fields = asdict(webhook)
+
+        if idempotency_key is not None:
+            webhook_fields['idempotency_key'] = idempotency_key
+
         await self.apify_client.webhooks().create(
+            **webhook_fields,
             actor_run_id=self.configuration.actor_run_id,
-            event_types=webhook.event_types,
-            request_url=webhook.request_url,
-            payload_template=webhook.payload_template,
-            headers_template=webhook.headers_template,
-            ignore_ssl_errors=webhook.ignore_ssl_errors,
-            do_not_retry=webhook.do_not_retry,
-            idempotency_key=idempotency_key if idempotency_key is not None else webhook.idempotency_key,
             is_ad_hoc=True,
         )
 
diff --git a/src/apify/_webhook.py b/src/apify/_webhook.py
index 129385c9..ff084f6a 100644
--- a/src/apify/_webhook.py
+++ b/src/apify/_webhook.py
@@ -48,15 +48,13 @@ def __post_init__(self) -> None:
 
 
 def to_client_representations(webhooks: list[Webhook] | None) -> list[WebhookRepresentation] | None:
-    """Project SDK webhooks to the minimal ad-hoc representation accepted by the client's `start()` / `call()`."""
+    """Convert SDK webhooks to the ad-hoc representation accepted by the client's `start()` / `call()`.
+
+    `Webhook`'s field names match `WebhookRepresentation`'s, so we let pydantic read them straight off the
+    instance rather than listing each one. This forwards any field the representation declares without changes
+    here, and never emits an undeclared field as a malformed snake_case extra.
+    """
     if not webhooks:
         return None
-    return [
-        WebhookRepresentation(
-            event_types=w.event_types,
-            request_url=w.request_url,
-            payload_template=w.payload_template,
-            headers_template=w.headers_template,
-        )
-        for w in webhooks
-    ]
+
+    return [WebhookRepresentation.model_validate(webhook, from_attributes=True) for webhook in webhooks]