diff --git a/src/core/handlers/HttpHandler.test.ts b/src/core/handlers/HttpHandler.test.ts
index 55f1e0c40..9217e40f8 100644
--- a/src/core/handlers/HttpHandler.test.ts
+++ b/src/core/handlers/HttpHandler.test.ts
@@ -216,3 +216,45 @@ describe('run', () => {
     expect(await run()).toBe('complete')
   })
 })
+
+describe('once', () => {
+  it('marks a matching one-time handler as used', async () => {
+    const handler = new HttpHandler(
+      'GET',
+      '/resource',
+      () => {
+        return HttpResponse.text('Mocked')
+      },
+      {
+        once: true,
+      },
+    )
+
+    const request = new Request(new URL('/resource', location.href))
+    const result = await handler.run({
+      request,
+    })
+
+    expect(handler.isUsed).toBe(true)
+    expect(result?.handler).toEqual(handler)
+    expect(await result?.response?.text()).toBe('Mocked')
+
+    const resultAfterUsed = await handler.run({
+      request,
+    })
+    expect(handler.isUsed).toBe(true)
+    expect(resultAfterUsed?.handler).toBeUndefined()
+  })
+
+  it('does not mark a non-matching one-time-handler as used', async () => {
+    const handler = new HttpHandler('GET', '/resource', () => undefined, {
+      once: true,
+    })
+
+    const result = await handler.run({
+      request: new Request(new URL('/non-matching', location.href)),
+    })
+
+    expect(result?.handler).toBeUndefined()
+  })
+})
diff --git a/src/core/utils/handleRequest.test.ts b/src/core/utils/handleRequest.test.ts
index 2f49662ea..ff0626edd 100644
--- a/src/core/utils/handleRequest.test.ts
+++ b/src/core/utils/handleRequest.test.ts
@@ -342,3 +342,47 @@ it('returns undefined without warning on a passthrough request', async () => {
   expect(callbacks.onPassthroughResponse).toHaveBeenNthCalledWith(1, request)
   expect(callbacks.onMockedResponse).not.toHaveBeenCalled()
 })
+
+it('marks the first matching one-time handler as used', async () => {
+  const { emitter } = setup()
+
+  const oneTimeHandler = http.get(
+    '/resource',
+    () => {
+      return HttpResponse.text('One-time')
+    },
+    { once: true },
+  )
+  const anotherHandler = http.get('/resource', () => {
+    return HttpResponse.text('Another')
+  })
+  const handlers: Array<RequestHandler> = [oneTimeHandler, anotherHandler]
+
+  const requestId = uuidv4()
+  const request = new Request('http://localhost/resource')
+  const firstResult = await handleRequest(
+    request,
+    requestId,
+    handlers,
+    options,
+    emitter,
+    callbacks,
+  )
+
+  expect(await firstResult?.text()).toBe('One-time')
+  expect(oneTimeHandler.isUsed).toBe(true)
+  expect(anotherHandler.isUsed).toBe(false)
+
+  const secondResult = await handleRequest(
+    request,
+    requestId,
+    handlers,
+    options,
+    emitter,
+    callbacks,
+  )
+
+  expect(await secondResult?.text()).toBe('Another')
+  expect(anotherHandler.isUsed).toBe(true)
+  expect(oneTimeHandler.isUsed).toBe(true)
+})