diff --git a/lib/types/identity-service-types.js b/lib/types/identity-service-types.js
--- a/lib/types/identity-service-types.js
+++ b/lib/types/identity-service-types.js
@@ -327,13 +327,23 @@
 
 export const identityDeviceTypeToPlatform: {
   +[identityDeviceType: IdentityDeviceType]: Platform,
-} = {
+} = Object.freeze({
   [identityDeviceTypes.WEB]: 'web',
   [identityDeviceTypes.ANDROID]: 'android',
   [identityDeviceTypes.IOS]: 'ios',
   [identityDeviceTypes.WINDOWS]: 'windows',
   [identityDeviceTypes.MAC_OS]: 'macos',
-};
+});
+
+export const platformToIdentityDeviceType: {
+  +[platform: Platform]: IdentityDeviceType,
+} = Object.freeze({
+  web: identityDeviceTypes.WEB,
+  android: identityDeviceTypes.ANDROID,
+  ios: identityDeviceTypes.IOS,
+  windows: identityDeviceTypes.WINDOWS,
+  macos: identityDeviceTypes.MAC_OS,
+});
 
 export const identityDeviceTypeValidator: TEnums = t.enums.of(
   values(identityDeviceTypes),
diff --git a/web/grpc/identity-service-client-wrapper.js b/web/grpc/identity-service-client-wrapper.js
--- a/web/grpc/identity-service-client-wrapper.js
+++ b/web/grpc/identity-service-client-wrapper.js
@@ -20,7 +20,6 @@
   type IdentityAuthResult,
   type IdentityNewDeviceKeyUpload,
   type IdentityExistingDeviceKeyUpload,
-  identityDeviceTypes,
   identityAuthResultValidator,
   type UserDevicesOlmInboundKeys,
   type DeviceOlmInboundKeys,
@@ -34,6 +33,7 @@
   type PeersDeviceLists,
   peersDeviceListsValidator,
   type IdentityPlatformDetails,
+  platformToIdentityDeviceType,
 } from 'lib/types/identity-service-types.js';
 import { getMessageForException } from 'lib/utils/errors.js';
 import { assertWithValidator } from 'lib/utils/validation-utils.js';
@@ -58,6 +58,7 @@
 
 class IdentityServiceClientWrapper implements IdentityServiceClient {
   overridedOpaqueFilepath: string;
+  platformDetails: PlatformDetails;
   authClient: ?IdentityAuthClient.IdentityClientServicePromiseClient;
   unauthClient: IdentityUnauthClient.IdentityClientServicePromiseClient;
   getNewDeviceKeyUpload: () => Promise<IdentityNewDeviceKeyUpload>;
@@ -71,6 +72,7 @@
     getExistingDeviceKeyUpload: () => Promise<IdentityExistingDeviceKeyUpload>,
   ) {
     this.overridedOpaqueFilepath = overridedOpaqueFilepath;
+    this.platformDetails = platformDetails;
     if (authLayer) {
       this.authClient = IdentityServiceClientWrapper.createAuthClient(
         platformDetails,
@@ -356,6 +358,7 @@
     const startRequestBytes = opaqueLogin.start(password);
 
     const deviceKeyUpload = authExistingDeviceKeyUpload(
+      this.platformDetails,
       identityDeviceKeyUpload,
     );
 
@@ -418,6 +421,7 @@
   ) => {
     const identityDeviceKeyUpload = await this.getExistingDeviceKeyUpload();
     const deviceKeyUpload = authExistingDeviceKeyUpload(
+      this.platformDetails,
       identityDeviceKeyUpload,
     );
 
@@ -453,7 +457,10 @@
     nonceChallengeResponse,
   ) => {
     const identityDeviceKeyUpload = await this.getNewDeviceKeyUpload();
-    const deviceKeyUpload = authNewDeviceKeyUpload(identityDeviceKeyUpload);
+    const deviceKeyUpload = authNewDeviceKeyUpload(
+      this.platformDetails,
+      identityDeviceKeyUpload,
+    );
     const { nonce, nonceSignature } = nonceChallengeResponse;
 
     const request = new SecondaryDeviceKeysUploadRequest();
@@ -750,6 +757,7 @@
 }
 
 function authNewDeviceKeyUpload(
+  platformDetails: PlatformDetails,
   uploadData: IdentityNewDeviceKeyUpload,
 ): DeviceKeyUpload {
   const {
@@ -776,6 +784,7 @@
   const notifPrekeyUpload = createPrekey(notifPrekey, notifPrekeySignature);
 
   const deviceKeyUpload = createDeviceKeyUpload(
+    platformDetails,
     identityKeyInfo,
     contentPrekeyUpload,
     notifPrekeyUpload,
@@ -787,6 +796,7 @@
 }
 
 function authExistingDeviceKeyUpload(
+  platformDetails: PlatformDetails,
   uploadData: IdentityExistingDeviceKeyUpload,
 ): DeviceKeyUpload {
   const {
@@ -811,6 +821,7 @@
   const notifPrekeyUpload = createPrekey(notifPrekey, notifPrekeySignature);
 
   const deviceKeyUpload = createDeviceKeyUpload(
+    platformDetails,
     identityKeyInfo,
     contentPrekeyUpload,
     notifPrekeyUpload,
@@ -837,6 +848,7 @@
 }
 
 function createDeviceKeyUpload(
+  platformDetails: PlatformDetails,
   identityKeyInfo: IdentityKeyInfo,
   contentPrekeyUpload: Prekey,
   notifPrekeyUpload: Prekey,
@@ -849,7 +861,9 @@
   deviceKeyUpload.setNotifUpload(notifPrekeyUpload);
   deviceKeyUpload.setOneTimeContentPrekeysList([...contentOneTimeKeys]);
   deviceKeyUpload.setOneTimeNotifPrekeysList([...notifOneTimeKeys]);
-  deviceKeyUpload.setDeviceType(identityDeviceTypes.WEB);
+  deviceKeyUpload.setDeviceType(
+    platformToIdentityDeviceType[platformDetails.platform],
+  );
   return deviceKeyUpload;
 }
 
diff --git a/web/grpc/interceptor.js b/web/grpc/interceptor.js
--- a/web/grpc/interceptor.js
+++ b/web/grpc/interceptor.js
@@ -33,7 +33,14 @@
     if (majorDesktopVersion) {
       metadata['major_desktop_version'] = majorDesktopVersion.toString();
     }
-    metadata['device_type'] = deviceType;
+
+    let identityDeviceType;
+    if (deviceType === 'macos') {
+      identityDeviceType = 'mac_os';
+    } else {
+      identityDeviceType = deviceType;
+    }
+    metadata['device_type'] = identityDeviceType;
 
     return invoker(request);
   }