diff --git a/src/core/HttpResponse.test.ts b/src/core/HttpResponse.test.ts
index d88984fa0..e5f10463f 100644
--- a/src/core/HttpResponse.test.ts
+++ b/src/core/HttpResponse.test.ts
@@ -253,18 +253,89 @@ describe('HttpResponse.html()', () => {
   })
 })
 
-it('creates an array buffer response', async () => {
-  const buffer = new TextEncoder().encode('hello world')
-  const response = HttpResponse.arrayBuffer(buffer)
+describe('HttpResponse.arrayBuffer()', () => {
+  it('creates an array buffer response', async () => {
+    const buffer = new TextEncoder().encode('hello world')
+    const response = HttpResponse.arrayBuffer(buffer)
 
-  expect(response.status).toBe(200)
-  expect(response.statusText).toBe('OK')
-  expect(response.body).toBeInstanceOf(ReadableStream)
+    expect(response.status).toBe(200)
+    expect(response.statusText).toBe('OK')
+    expect(response.body).toBeInstanceOf(ReadableStream)
 
-  const responseData = await response.arrayBuffer()
-  expect(responseData).toEqual(buffer.buffer)
-  expect(Object.fromEntries(response.headers.entries())).toEqual({
-    'content-length': '11',
+    const responseData = await response.arrayBuffer()
+    expect(responseData).toEqual(buffer.buffer)
+    expect(Object.fromEntries(response.headers.entries())).toEqual({
+      'content-length': '11',
+      'content-type': 'application/octet-stream',
+    })
+  })
+
+  it('allows overriding the "Content-Type" response header', async () => {
+    const buffer = new TextEncoder().encode('hello world')
+    const response = HttpResponse.arrayBuffer(buffer, {
+      headers: {
+        'Content-Type': 'text/plain; charset=utf-8',
+      },
+    })
+
+    expect(response.status).toBe(200)
+    expect(response.statusText).toBe('OK')
+    expect(response.body).toBeInstanceOf(ReadableStream)
+
+    const responseData = await response.arrayBuffer()
+    expect(responseData).toEqual(buffer.buffer)
+    expect(Object.fromEntries(response.headers.entries())).toEqual({
+      'content-length': '11',
+      'content-type': 'text/plain; charset=utf-8',
+    })
+  })
+
+  it('creates an array buffer response from a shared array buffer', async () => {
+    const arrayBuffer = new TextEncoder().encode('hello world')
+
+    // Copy the data from the array buffer to a shared array buffer
+    const sharedBuffer = new SharedArrayBuffer(11)
+    const sharedView = new Uint8Array(sharedBuffer)
+    sharedView.set(arrayBuffer)
+
+    const response = HttpResponse.arrayBuffer(sharedBuffer)
+
+    expect(response.status).toBe(200)
+    expect(response.statusText).toBe('OK')
+    expect(response.body).toBeInstanceOf(ReadableStream)
+
+    const responseData = await response.arrayBuffer()
+    expect(responseData).toEqual(arrayBuffer.buffer)
+    expect(Object.fromEntries(response.headers.entries())).toEqual({
+      'content-length': '11',
+      'content-type': 'application/octet-stream',
+    })
+  })
+
+  it('allows overriding the "Content-Type" response header for shared array buffers', async () => {
+    const arrayBuffer = new TextEncoder().encode('hello world')
+
+    // Copy the data from the array buffer to a shared array buffer
+    const sharedBuffer = new SharedArrayBuffer(11)
+    const sharedView = new Uint8Array(sharedBuffer)
+    sharedView.set(arrayBuffer)
+
+    const response = HttpResponse.arrayBuffer(sharedBuffer, {
+      headers: {
+        'Content-Type': 'text/plain; charset=utf-8',
+      },
+    })
+
+    expect(response.status).toBe(200)
+    expect(response.statusText).toBe('OK')
+    expect(response.body).toBeInstanceOf(ReadableStream)
+
+    const responseData = await response.arrayBuffer()
+    expect(responseData).toEqual(arrayBuffer.buffer)
+    expect(Object.fromEntries(response.headers.entries())).toEqual({
+      'content-length': '11',
+      'content-type': 'text/plain; charset=utf-8',
+    })
   })
 })
 
diff --git a/src/core/HttpResponse.ts b/src/core/HttpResponse.ts
index ca62ca768..7df08d54f 100644
--- a/src/core/HttpResponse.ts
+++ b/src/core/HttpResponse.ts
@@ -153,9 +153,16 @@ export class HttpResponse extends Response {
    *
    * HttpResponse.arrayBuffer(buffer)
    */
-  static arrayBuffer(body?: ArrayBuffer, init?: HttpResponseInit): Response {
+  static arrayBuffer(
+    body?: ArrayBuffer | SharedArrayBuffer,
+    init?: HttpResponseInit,
+  ): Response {
     const responseInit = normalizeResponseInit(init)
 
+    if (!responseInit.headers.has('Content-Type')) {
+      responseInit.headers.set('Content-Type', 'application/octet-stream')
+    }
+
     if (body && !responseInit.headers.has('Content-Length')) {
       responseInit.headers.set('Content-Length', body.byteLength.toString())
     }