diff --git a/src/clients/channels-client.test.ts b/src/clients/channels-client.test.ts
new file mode 100644
index 0000000..02370c0
--- /dev/null
+++ b/src/clients/channels-client.test.ts
@@ -0,0 +1,66 @@
+import { http, HttpResponse } from 'msw'
+import { describe, expect, it } from 'vitest'
+import { CommsApi } from '../comms-api'
+import { server } from '../testUtils/msw-setup'
+import {
+    TEST_API_BASE_URL as BASE,
+    TEST_API_TOKEN,
+    TEST_CHANNEL_ID,
+} from '../testUtils/test-defaults'
+
+const CHANNEL_RESPONSE = {
+    id: TEST_CHANNEL_ID,
+    name: 'General',
+    creator: 1,
+    public: true,
+    workspace_id: 1,
+    archived: false,
+    created_ts: 1_609_459_200,
+    version: 1,
+}
+
+describe('ChannelsClient — wire serialization', () => {
+    it.each([
+        ['createChannel', true],
+        ['createChannel', false],
+        ['updateChannel', true],
+        ['updateChannel', false],
+    ] as const)(
+        '%s sends use_default_recipients: %s and empty default audience arrays',
+        async (method, useDefaultRecipients) => {
+            const suffix = method === 'createChannel' ? 'add' : 'update'
+            let body: Record<string, unknown> | undefined
+            server.use(
+                http.post(`${BASE}/channels/${suffix}`, async ({ request }) => {
+                    body = (await request.json()) as Record<string, unknown>
+                    return HttpResponse.json(CHANNEL_RESPONSE)
+                }),
+            )
+
+            const api = new CommsApi(TEST_API_TOKEN)
+            if (method === 'createChannel') {
+                await api.channels.createChannel({
+                    workspaceId: 1,
+                    name: 'General',
+                    useDefaultRecipients,
+                    defaultGroups: [],
+                    defaultRecipients: [],
+                })
+            } else {
+                await api.channels.updateChannel({
+                    id: TEST_CHANNEL_ID,
+                    name: 'General',
+                    useDefaultRecipients,
+                    defaultGroups: [],
+                    defaultRecipients: [],
+                })
+            }
+
+            expect(body).toMatchObject({
+                use_default_recipients: useDefaultRecipients,
+                default_groups: [],
+                default_recipients: [],
+            })
+        },
+    )
+})
diff --git a/src/types/requests.ts b/src/types/requests.ts
index 5249d7f..24734ca 100644
--- a/src/types/requests.ts
+++ b/src/types/requests.ts
@@ -18,6 +18,7 @@ export const CreateChannelArgsSchema = z.object({
     color: z.number().nullable().optional(),
     public: z.boolean().nullable().optional(),
     description: z.string().nullable().optional(),
+    useDefaultRecipients: z.boolean().nullable().optional(),
     defaultGroups: z.array(z.string()).nullable().optional(),
     defaultRecipients: z.array(z.number()).nullable().optional(),
     isFavorited: z.boolean().nullable().optional(),
@@ -32,6 +33,7 @@ export const UpdateChannelArgsSchema = z.object({
     color: z.number().nullable().optional(),
     public: z.boolean().nullable().optional(),
     description: z.string().nullable().optional(),
+    useDefaultRecipients: z.boolean().nullable().optional(),
     defaultGroups: z.array(z.string()).nullable().optional(),
     defaultRecipients: z.array(z.number()).nullable().optional(),
     isFavorited: z.boolean().nullable().optional(),