diff --git a/docs/docs/api/Dispatcher.md b/docs/docs/api/Dispatcher.md
index 1c51b4ba309..5e28aaefe09 100644
--- a/docs/docs/api/Dispatcher.md
+++ b/docs/docs/api/Dispatcher.md
@@ -207,7 +207,7 @@ Returns: `Boolean` - `false` if dispatcher is busy and further dispatch calls wo
 
 * **onRequestStart** `(controller: DispatchController, context: object) => void` - Invoked before request is dispatched on socket. May be invoked multiple times when a request is retried when the request at the head of the pipeline fails.
 * **onRequestUpgrade** `(controller: DispatchController, statusCode: number, headers: Record<string, string | string[]>, socket: Duplex) => void` (optional) - Invoked when request is upgraded. Required if `DispatchOptions.upgrade` is defined or `DispatchOptions.method === 'CONNECT'`.
-* **onResponseStart** `(controller: DispatchController, statusCode: number, statusMessage?: string, headers: Record<string, string | string []>) => void` - Invoked when statusCode and headers have been received. May be invoked multiple times due to 1xx informational headers. Not required for `upgrade` requests.
+* **onResponseStart** `(controller: DispatchController, statusCode: number, headers: Record<string, string | string []>, statusMessage?: string) => void` - Invoked when statusCode and headers have been received. May be invoked multiple times due to 1xx informational headers. Not required for `upgrade` requests.
 * **onResponseData** `(controller: DispatchController, chunk: Buffer) => void` - Invoked when response payload data is received. Not required for `upgrade` requests.
 * **onResponseEnd** `(controller: DispatchController, trailers: Record<string, string | string[]>) => void` - Invoked when response payload and trailers have been received and the request has completed. Not required for `upgrade` requests.
 * **onResponseError** `(error: Error) => void` - Invoked when an error has occurred. May not throw.
diff --git a/lib/handler/cache-handler.js b/lib/handler/cache-handler.js
index 36dc65c1c68..059be122e52 100644
--- a/lib/handler/cache-handler.js
+++ b/lib/handler/cache-handler.js
@@ -71,15 +71,15 @@ class CacheHandler {
   onResponseStart (
     controller,
     statusCode,
-    statusMessage,
-    headers
+    headers,
+    statusMessage
   ) {
     const downstreamOnHeaders = () =>
       this.#handler.onResponseStart?.(
         controller,
         statusCode,
-        statusMessage,
-        headers
+        headers,
+        statusMessage
       )
 
     if (
diff --git a/lib/handler/cache-revalidation-handler.js b/lib/handler/cache-revalidation-handler.js
index 96a70683ea8..9672936d9de 100644
--- a/lib/handler/cache-revalidation-handler.js
+++ b/lib/handler/cache-revalidation-handler.js
@@ -62,8 +62,8 @@ class CacheRevalidationHandler {
   onResponseStart (
     controller,
     statusCode,
-    statusMessage,
-    headers
+    headers,
+    statusMessage
   ) {
     assert(this.#callback != null)
 
@@ -82,8 +82,8 @@ class CacheRevalidationHandler {
     this.#handler.onResponseStart?.(
       controller,
       statusCode,
-      statusMessage,
-      headers
+      headers,
+      statusMessage
     )
   }
 
@@ -92,7 +92,7 @@ class CacheRevalidationHandler {
       return
     }
 
-    return this.#handler.onResponseData(controller, chunk)
+    return this.#handler.onResponseData?.(controller, chunk)
   }
 
   onResponseEnd (controller, trailers) {
diff --git a/lib/handler/redirect-handler.js b/lib/handler/redirect-handler.js
index d6f1995ced1..dd28e1d7426 100644
--- a/lib/handler/redirect-handler.js
+++ b/lib/handler/redirect-handler.js
@@ -90,7 +90,7 @@ class RedirectHandler {
     this.handler.onRequestUpgrade?.(controller, statusCode, headers, socket)
   }
 
-  onResponseStart (controller, statusCode, statusMessage, headers) {
+  onResponseStart (controller, statusCode, headers, statusMessage) {
     if (this.opts.throwOnMaxRedirect && this.history.length >= this.maxRedirections) {
       throw new Error('max redirects')
     }
@@ -125,7 +125,7 @@ class RedirectHandler {
     }
 
     if (!this.location) {
-      this.handler.onResponseStart?.(controller, statusCode, statusMessage, headers)
+      this.handler.onResponseStart?.(controller, statusCode, headers, statusMessage)
       return
     }
 
diff --git a/lib/handler/unwrap-handler.js b/lib/handler/unwrap-handler.js
index a6b44d99876..865593a327b 100644
--- a/lib/handler/unwrap-handler.js
+++ b/lib/handler/unwrap-handler.js
@@ -73,7 +73,7 @@ module.exports = class UnwrapHandler {
 
   onHeaders (statusCode, rawHeaders, resume, statusMessage) {
     this.#controller[kResume] = resume
-    this.#handler.onResponseStart?.(this.#controller, statusCode, statusMessage, parseHeaders(rawHeaders))
+    this.#handler.onResponseStart?.(this.#controller, statusCode, parseHeaders(rawHeaders), statusMessage)
     return !this.#controller.paused
   }
 
diff --git a/lib/handler/wrap-handler.js b/lib/handler/wrap-handler.js
index 3bf49f1be16..271bfb8a177 100644
--- a/lib/handler/wrap-handler.js
+++ b/lib/handler/wrap-handler.js
@@ -60,7 +60,7 @@ module.exports = class WrapHandler {
     this.#handler.onUpgrade?.(statusCode, rawHeaders, socket)
   }
 
-  onResponseStart (controller, statusCode, statusMessage, headers) {
+  onResponseStart (controller, statusCode, headers, statusMessage) {
     const rawHeaders = []
     for (const [key, val] of Object.entries(headers)) {
       // TODO (fix): What if val is Array
diff --git a/lib/interceptor/cache.js b/lib/interceptor/cache.js
index d48ac564b42..703b87782ea 100644
--- a/lib/interceptor/cache.js
+++ b/lib/interceptor/cache.js
@@ -163,7 +163,7 @@ function sendCachedValue (handler, opts, result, age, context) {
   // TODO (fix): What if headers.age already exists?
   const headers = age != null ? { ...result.headers, age: String(age) } : result.headers
 
-  handler.onResponseStart?.(controller, result.statusCode, result.statusMessage, headers)
+  handler.onResponseStart?.(controller, result.statusCode, headers, result.statusMessage)
 
   if (opts.method === 'HEAD') {
     stream.destroy()
diff --git a/types/dispatcher.d.ts b/types/dispatcher.d.ts
index 3c3a32c47f0..17bb44166fa 100644
--- a/types/dispatcher.d.ts
+++ b/types/dispatcher.d.ts
@@ -226,7 +226,7 @@ declare namespace Dispatcher {
   export interface DispatchHandler {
     onRequestStart?(controller: DispatchController, context: any): void;
     onRequestUpgrade?(controller: DispatchController, statusCode: number, headers: IncomingHttpHeaders, socket: Duplex): void;
-    onResponseStart?(controller: DispatchController, statusCode: number, statusMessage: string | null, headers: IncomingHttpHeaders): void;
+    onResponseStart?(controller: DispatchController, statusCode: number, headers: IncomingHttpHeaders, statusMessage?: string): void;
     onResponseData?(controller: DispatchController, chunk: Buffer): void;
     onResponseEnd?(controller: DispatchController, trailers: IncomingHttpHeaders): void;
     onResponseError?(controller: DispatchController, error: Error): void;