diff --git a/src/common/lib/client/auth.ts b/src/common/lib/client/auth.ts
index 721d23e394..1a47291c08 100644
--- a/src/common/lib/client/auth.ts
+++ b/src/common/lib/client/auth.ts
@@ -12,6 +12,7 @@ import HttpMethods from '../../constants/HttpMethods';
 import HttpStatusCodes from 'common/constants/HttpStatusCodes';
 import Platform from '../../platform';
 import Resource from './resource';
+import Defaults from '../util/defaults';
 
 type BatchResult<T> = API.Types.BatchResult<T>;
 type TokenRevocationTargetSpecifier = API.Types.TokenRevocationTargetSpecifier;
@@ -584,7 +585,7 @@ class Auth {
           return client.baseUri(host) + path;
         };
 
-      const requestHeaders = Utils.defaultPostHeaders(this.client.options);
+      const requestHeaders = Defaults.defaultPostHeaders(this.client.options);
       if (authOptions.requestHeaders) Utils.mixin(requestHeaders, authOptions.requestHeaders);
       Logger.logAction(
         Logger.LOG_MICRO,
@@ -1073,7 +1074,7 @@ class Auth {
     };
 
     const format = this.client.options.useBinaryProtocol ? Utils.Format.msgpack : Utils.Format.json,
-      headers = Utils.defaultPostHeaders(this.client.options, { format });
+      headers = Defaults.defaultPostHeaders(this.client.options, { format });
 
     if (this.client.options.headers) Utils.mixin(headers, this.client.options.headers);
 
diff --git a/src/common/lib/client/baseclient.ts b/src/common/lib/client/baseclient.ts
index f81d69f4e2..1486df07b5 100644
--- a/src/common/lib/client/baseclient.ts
+++ b/src/common/lib/client/baseclient.ts
@@ -118,7 +118,7 @@ class BaseClient {
         return Utils.promisify(this, 'stats', [params]) as Promise<PaginatedResult<Stats>>;
       }
     }
-    const headers = Utils.defaultGetHeaders(this.options),
+    const headers = Defaults.defaultGetHeaders(this.options),
       format = this.options.useBinaryProtocol ? Utils.Format.msgpack : Utils.Format.json,
       envelope = this.http.supportsLinkHeaders ? undefined : format;
 
@@ -148,7 +148,7 @@ class BaseClient {
 
     const _callback = callback || noop;
 
-    const headers = Utils.defaultGetHeaders(this.options);
+    const headers = Defaults.defaultGetHeaders(this.options);
     if (this.options.headers) Utils.mixin(headers, this.options.headers);
     const timeUri = (host: string) => {
       return this.baseUri(host) + '/time';
@@ -201,8 +201,8 @@ class BaseClient {
     const _method = method.toLowerCase() as HttpMethods;
     const headers =
       _method == 'get'
-        ? Utils.defaultGetHeaders(this.options, { format, protocolVersion: version })
-        : Utils.defaultPostHeaders(this.options, { format, protocolVersion: version });
+        ? Defaults.defaultGetHeaders(this.options, { format, protocolVersion: version })
+        : Defaults.defaultPostHeaders(this.options, { format, protocolVersion: version });
 
     if (callback === undefined) {
       return Utils.promisify(this, 'request', [method, path, version, params, body, customHeaders]) as Promise<
@@ -264,7 +264,7 @@ class BaseClient {
     }
 
     const format = this.options.useBinaryProtocol ? Utils.Format.msgpack : Utils.Format.json,
-      headers = Utils.defaultPostHeaders(this.options, { format });
+      headers = Defaults.defaultPostHeaders(this.options, { format });
 
     if (this.options.headers) Utils.mixin(headers, this.options.headers);
 
@@ -304,7 +304,7 @@ class BaseClient {
     }
 
     const format = this.options.useBinaryProtocol ? Utils.Format.msgpack : Utils.Format.json,
-      headers = Utils.defaultPostHeaders(this.options, { format });
+      headers = Defaults.defaultPostHeaders(this.options, { format });
 
     if (this.options.headers) Utils.mixin(headers, this.options.headers);
 
diff --git a/src/common/lib/client/channel.ts b/src/common/lib/client/channel.ts
index b195ecf370..d14f4c9752 100644
--- a/src/common/lib/client/channel.ts
+++ b/src/common/lib/client/channel.ts
@@ -11,6 +11,7 @@ import { PaginatedResultCallback, StandardCallback } from '../../types/utils';
 import BaseClient from './baseclient';
 import * as API from '../../../../ably';
 import Platform from 'common/platform';
+import Defaults from '../util/defaults';
 
 interface RestHistoryParams {
   start?: number;
@@ -88,7 +89,7 @@ class Channel extends EventEmitter {
     const client = this.client,
       format = client.options.useBinaryProtocol ? Utils.Format.msgpack : Utils.Format.json,
       envelope = this.client.http.supportsLinkHeaders ? undefined : format,
-      headers = Utils.defaultGetHeaders(client.options, { format });
+      headers = Defaults.defaultGetHeaders(client.options, { format });
 
     Utils.mixin(headers, client.options.headers);
 
@@ -141,7 +142,7 @@ class Channel extends EventEmitter {
       options = client.options,
       format = options.useBinaryProtocol ? Utils.Format.msgpack : Utils.Format.json,
       idempotentRestPublishing = client.options.idempotentRestPublishing,
-      headers = Utils.defaultPostHeaders(client.options, { format });
+      headers = Defaults.defaultPostHeaders(client.options, { format });
 
     Utils.mixin(headers, options.headers);
 
@@ -190,7 +191,7 @@ class Channel extends EventEmitter {
     }
 
     const format = this.client.options.useBinaryProtocol ? Utils.Format.msgpack : Utils.Format.json;
-    const headers = Utils.defaultPostHeaders(this.client.options, { format });
+    const headers = Defaults.defaultPostHeaders(this.client.options, { format });
 
     Resource.get<API.Types.ChannelDetails>(this.client, this.basePath, headers, {}, format, callback || noop);
   }
diff --git a/src/common/lib/client/presence.ts b/src/common/lib/client/presence.ts
index 18cb5a2b97..ea64ad3cd7 100644
--- a/src/common/lib/client/presence.ts
+++ b/src/common/lib/client/presence.ts
@@ -7,6 +7,7 @@ import { CipherOptions } from '../types/message';
 import { PaginatedResultCallback } from '../../types/utils';
 import Channel from './channel';
 import RealtimeChannel from './realtimechannel';
+import Defaults from '../util/defaults';
 
 class Presence extends EventEmitter {
   channel: RealtimeChannel | Channel;
@@ -32,7 +33,7 @@ class Presence extends EventEmitter {
     const client = this.channel.client,
       format = client.options.useBinaryProtocol ? Utils.Format.msgpack : Utils.Format.json,
       envelope = this.channel.client.http.supportsLinkHeaders ? undefined : format,
-      headers = Utils.defaultGetHeaders(client.options, { format });
+      headers = Defaults.defaultGetHeaders(client.options, { format });
 
     Utils.mixin(headers, client.options.headers);
 
@@ -71,7 +72,7 @@ class Presence extends EventEmitter {
     const client = this.channel.client,
       format = client.options.useBinaryProtocol ? Utils.Format.msgpack : Utils.Format.json,
       envelope = this.channel.client.http.supportsLinkHeaders ? undefined : format,
-      headers = Utils.defaultGetHeaders(client.options, { format });
+      headers = Defaults.defaultGetHeaders(client.options, { format });
 
     Utils.mixin(headers, client.options.headers);
 
diff --git a/src/common/lib/client/push.ts b/src/common/lib/client/push.ts
index 0a60822cbd..2cf3e01d19 100644
--- a/src/common/lib/client/push.ts
+++ b/src/common/lib/client/push.ts
@@ -6,6 +6,7 @@ import ErrorInfo from '../types/errorinfo';
 import PushChannelSubscription from '../types/pushchannelsubscription';
 import { ErrCallback, PaginatedResultCallback, StandardCallback } from '../../types/utils';
 import BaseClient from './baseclient';
+import Defaults from '../util/defaults';
 
 class Push {
   client: BaseClient;
@@ -31,7 +32,7 @@ class Admin {
   publish(recipient: any, payload: any, callback: ErrCallback) {
     const client = this.client;
     const format = client.options.useBinaryProtocol ? Utils.Format.msgpack : Utils.Format.json,
-      headers = Utils.defaultPostHeaders(client.options, { format }),
+      headers = Defaults.defaultPostHeaders(client.options, { format }),
       params = {};
     const body = Utils.mixin({ recipient: recipient }, payload);
 
@@ -59,7 +60,7 @@ class DeviceRegistrations {
     const client = this.client;
     const body = DeviceDetails.fromValues(device);
     const format = client.options.useBinaryProtocol ? Utils.Format.msgpack : Utils.Format.json,
-      headers = Utils.defaultPostHeaders(client.options, { format }),
+      headers = Defaults.defaultPostHeaders(client.options, { format }),
       params = {};
 
     if (typeof callback !== 'function') {
@@ -95,7 +96,7 @@ class DeviceRegistrations {
   get(deviceIdOrDetails: any, callback: StandardCallback<DeviceDetails>) {
     const client = this.client,
       format = client.options.useBinaryProtocol ? Utils.Format.msgpack : Utils.Format.json,
-      headers = Utils.defaultGetHeaders(client.options, { format }),
+      headers = Defaults.defaultGetHeaders(client.options, { format }),
       deviceId = deviceIdOrDetails.id || deviceIdOrDetails;
 
     if (typeof callback !== 'function') {
@@ -139,7 +140,7 @@ class DeviceRegistrations {
     const client = this.client,
       format = client.options.useBinaryProtocol ? Utils.Format.msgpack : Utils.Format.json,
       envelope = this.client.http.supportsLinkHeaders ? undefined : format,
-      headers = Utils.defaultGetHeaders(client.options, { format });
+      headers = Defaults.defaultGetHeaders(client.options, { format });
 
     if (typeof callback !== 'function') {
       return Utils.promisify(this, 'list', arguments);
@@ -159,7 +160,7 @@ class DeviceRegistrations {
   remove(deviceIdOrDetails: any, callback: ErrCallback) {
     const client = this.client,
       format = client.options.useBinaryProtocol ? Utils.Format.msgpack : Utils.Format.json,
-      headers = Utils.defaultGetHeaders(client.options, { format }),
+      headers = Defaults.defaultGetHeaders(client.options, { format }),
       params = {},
       deviceId = deviceIdOrDetails.id || deviceIdOrDetails;
 
@@ -195,7 +196,7 @@ class DeviceRegistrations {
   removeWhere(params: any, callback: ErrCallback) {
     const client = this.client,
       format = client.options.useBinaryProtocol ? Utils.Format.msgpack : Utils.Format.json,
-      headers = Utils.defaultGetHeaders(client.options, { format });
+      headers = Defaults.defaultGetHeaders(client.options, { format });
 
     if (typeof callback !== 'function') {
       return Utils.promisify(this, 'removeWhere', arguments);
@@ -220,7 +221,7 @@ class ChannelSubscriptions {
     const client = this.client;
     const body = PushChannelSubscription.fromValues(subscription);
     const format = client.options.useBinaryProtocol ? Utils.Format.msgpack : Utils.Format.json,
-      headers = Utils.defaultPostHeaders(client.options, { format }),
+      headers = Defaults.defaultPostHeaders(client.options, { format }),
       params = {};
 
     if (typeof callback !== 'function') {
@@ -252,7 +253,7 @@ class ChannelSubscriptions {
     const client = this.client,
       format = client.options.useBinaryProtocol ? Utils.Format.msgpack : Utils.Format.json,
       envelope = this.client.http.supportsLinkHeaders ? undefined : format,
-      headers = Utils.defaultGetHeaders(client.options, { format });
+      headers = Defaults.defaultGetHeaders(client.options, { format });
 
     if (typeof callback !== 'function') {
       return Utils.promisify(this, 'list', arguments);
@@ -272,7 +273,7 @@ class ChannelSubscriptions {
   removeWhere(params: any, callback: PaginatedResultCallback<unknown>) {
     const client = this.client,
       format = client.options.useBinaryProtocol ? Utils.Format.msgpack : Utils.Format.json,
-      headers = Utils.defaultGetHeaders(client.options, { format });
+      headers = Defaults.defaultGetHeaders(client.options, { format });
 
     if (typeof callback !== 'function') {
       return Utils.promisify(this, 'removeWhere', arguments);
@@ -292,7 +293,7 @@ class ChannelSubscriptions {
     const client = this.client,
       format = client.options.useBinaryProtocol ? Utils.Format.msgpack : Utils.Format.json,
       envelope = this.client.http.supportsLinkHeaders ? undefined : format,
-      headers = Utils.defaultGetHeaders(client.options, { format });
+      headers = Defaults.defaultGetHeaders(client.options, { format });
 
     if (typeof callback !== 'function') {
       return Utils.promisify(this, 'listChannels', arguments);
diff --git a/src/common/lib/util/defaults.ts b/src/common/lib/util/defaults.ts
index 1b1fd275fe..23d73aee98 100644
--- a/src/common/lib/util/defaults.ts
+++ b/src/common/lib/util/defaults.ts
@@ -42,6 +42,8 @@ type CompleteDefaults = IDefaults & {
   getRealtimeHost(options: ClientOptions, production: boolean, environment: string): string;
   objectifyOptions(options: ClientOptions | string): ClientOptions;
   normaliseOptions(options: InternalClientOptions): NormalisedClientOptions;
+  defaultGetHeaders(options: NormalisedClientOptions, headersOptions?: HeadersOptions): Record<string, string>;
+  defaultPostHeaders(options: NormalisedClientOptions, headersOptions?: HeadersOptions): Record<string, string>;
 };
 
 const Defaults = {
@@ -87,6 +89,8 @@ const Defaults = {
   checkHost,
   objectifyOptions,
   normaliseOptions,
+  defaultGetHeaders,
+  defaultPostHeaders,
 };
 
 export function getHost(options: ClientOptions, host?: string | null, ws?: boolean): string {
@@ -260,6 +264,56 @@ export function normaliseOptions(options: InternalClientOptions): NormalisedClie
   };
 }
 
+const contentTypes = {
+  json: 'application/json',
+  xml: 'application/xml',
+  html: 'text/html',
+  msgpack: 'application/x-msgpack',
+};
+
+export interface HeadersOptions {
+  format?: Utils.Format;
+  protocolVersion?: number;
+}
+
+const defaultHeadersOptions: Required<HeadersOptions> = {
+  format: Utils.Format.json,
+  protocolVersion: Defaults.protocolVersion,
+};
+
+export function defaultGetHeaders(
+  options: NormalisedClientOptions,
+  {
+    format = defaultHeadersOptions.format,
+    protocolVersion = defaultHeadersOptions.protocolVersion,
+  }: HeadersOptions = {}
+): Record<string, string> {
+  const accept = contentTypes[format];
+  return {
+    accept: accept,
+    'X-Ably-Version': protocolVersion.toString(),
+    'Ably-Agent': getAgentString(options),
+  };
+}
+
+export function defaultPostHeaders(
+  options: NormalisedClientOptions,
+  {
+    format = defaultHeadersOptions.format,
+    protocolVersion = defaultHeadersOptions.protocolVersion,
+  }: HeadersOptions = {}
+): Record<string, string> {
+  let contentType;
+  const accept = (contentType = contentTypes[format]);
+
+  return {
+    accept: accept,
+    'content-type': contentType,
+    'X-Ably-Version': protocolVersion.toString(),
+    'Ably-Agent': getAgentString(options),
+  };
+}
+
 export default Defaults as CompleteDefaults;
 
 export function getDefaults(platformDefaults: IDefaults) {
diff --git a/src/common/lib/util/utils.ts b/src/common/lib/util/utils.ts
index 8d8477a2ee..03d546b0a8 100644
--- a/src/common/lib/util/utils.ts
+++ b/src/common/lib/util/utils.ts
@@ -1,7 +1,5 @@
 import Platform from 'common/platform';
-import Defaults, { getAgentString } from './defaults';
 import ErrorInfo, { PartialErrorInfo } from 'common/lib/types/errorinfo';
-import { NormalisedClientOptions } from 'common/types/ClientOptions';
 
 function randomPosn(arrOrStr: Array<unknown> | string) {
   return Math.floor(Math.random() * arrOrStr.length);
@@ -330,61 +328,11 @@ export function allSame(arr: Array<Record<string, unknown>>, prop: string): bool
   });
 }
 
-const contentTypes = {
-  json: 'application/json',
-  xml: 'application/xml',
-  html: 'text/html',
-  msgpack: 'application/x-msgpack',
-};
-
 export enum Format {
   msgpack = 'msgpack',
   json = 'json',
 }
 
-export interface HeadersOptions {
-  format?: Format;
-  protocolVersion?: number;
-}
-
-const defaultHeadersOptions: Required<HeadersOptions> = {
-  format: Format.json,
-  protocolVersion: Defaults.protocolVersion,
-};
-
-export function defaultGetHeaders(
-  options: NormalisedClientOptions,
-  {
-    format = defaultHeadersOptions.format,
-    protocolVersion = defaultHeadersOptions.protocolVersion,
-  }: HeadersOptions = {}
-): Record<string, string> {
-  const accept = contentTypes[format];
-  return {
-    accept: accept,
-    'X-Ably-Version': protocolVersion.toString(),
-    'Ably-Agent': getAgentString(options),
-  };
-}
-
-export function defaultPostHeaders(
-  options: NormalisedClientOptions,
-  {
-    format = defaultHeadersOptions.format,
-    protocolVersion = defaultHeadersOptions.protocolVersion,
-  }: HeadersOptions = {}
-): Record<string, string> {
-  let contentType;
-  const accept = (contentType = contentTypes[format]);
-
-  return {
-    accept: accept,
-    'content-type': contentType,
-    'X-Ably-Version': protocolVersion.toString(),
-    'Ably-Agent': getAgentString(options),
-  };
-}
-
 export function arrPopRandomElement<T>(arr: Array<T>): T {
   return arr.splice(randomPosn(arr), 1)[0];
 }