diff --git a/src/event-handler/index.ts b/src/event-handler/index.ts
index e86c12cf..ea6bd98d 100644
--- a/src/event-handler/index.ts
+++ b/src/event-handler/index.ts
@@ -20,8 +20,10 @@ interface EventHandler<TTransformed> {
     event: E | E[],
     callback: HandlerFunction<E, TTransformed>,
   ): void;
-  onAny(handler: (event: EmitterWebhookEvent) => any): void;
-  onError(handler: (event: WebhookEventHandlerError) => any): void;
+  onAny(handler: (event: EmitterWebhookEvent & TTransformed) => any): void;
+  onError(
+    handler: (event: WebhookEventHandlerError<TTransformed>) => any,
+  ): void;
   removeListener<E extends EmitterWebhookEventName>(
     event: E | E[],
     callback: HandlerFunction<E, TTransformed>,
@@ -43,8 +45,8 @@ export function createEventHandler<TTransformed>(
 
   return {
     on: on.bind(null, state),
-    onAny: onAny.bind(null, state),
-    onError: onError.bind(null, state),
+    onAny: (onAny<TTransformed>).bind(null, state),
+    onError: (onError<TTransformed>).bind(null, state),
     removeListener: removeListener.bind(null, state),
     receive: receive.bind(null, state),
   };
diff --git a/src/event-handler/on.ts b/src/event-handler/on.ts
index cbec9162..e95e6216 100644
--- a/src/event-handler/on.ts
+++ b/src/event-handler/on.ts
@@ -49,16 +49,16 @@ export function receiverOn(
   handleEventHandlers(state, webhookNameOrNames, handler);
 }
 
-export function receiverOnAny(
+export function receiverOnAny<TTransformed>(
   state: State,
-  handler: (event: EmitterWebhookEvent) => any,
+  handler: (event: EmitterWebhookEvent & TTransformed) => any,
 ) {
   handleEventHandlers(state, "*", handler);
 }
 
-export function receiverOnError(
+export function receiverOnError<TTransformed>(
   state: State,
-  handler: (event: WebhookEventHandlerError) => any,
+  handler: (event: WebhookEventHandlerError<TTransformed>) => any,
 ) {
   handleEventHandlers(state, "error", handler);
 }
diff --git a/src/index.ts b/src/index.ts
index d5c3ed6d..373cb2a6 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -25,8 +25,12 @@ class Webhooks<TTransformed = unknown> {
     event: E | E[],
     callback: HandlerFunction<E, TTransformed>,
   ) => void;
-  public onAny: (callback: (event: EmitterWebhookEvent) => any) => void;
-  public onError: (callback: (event: WebhookEventHandlerError) => any) => void;
+  public onAny: (
+    callback: (event: EmitterWebhookEvent & TTransformed) => any,
+  ) => void;
+  public onError: (
+    callback: (event: WebhookEventHandlerError<TTransformed>) => any,
+  ) => void;
   public removeListener: <E extends EmitterWebhookEventName | "*">(
     event: E | E[],
     callback: RemoveHandlerFunction<E, TTransformed>,
diff --git a/src/types.ts b/src/types.ts
index 1acfe1a9..d3c92ca7 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -62,8 +62,9 @@ export interface State extends Options<any> {
 export type WebhookError = Error & Partial<RequestError>;
 
 // todo: rename to "EmitterErrorEvent"
-export interface WebhookEventHandlerError extends AggregateError<WebhookError> {
-  event: EmitterWebhookEvent;
+export interface WebhookEventHandlerError<TTransformed = unknown>
+  extends AggregateError<WebhookError> {
+  event: EmitterWebhookEvent & TTransformed;
 }
 
 /**