diff --git a/keyserver/src/session/cookies.js b/keyserver/src/session/cookies.js
--- a/keyserver/src/session/cookies.js
+++ b/keyserver/src/session/cookies.js
@@ -9,6 +9,7 @@
 import { hasMinCodeVersion } from 'lib/shared/version-utils.js';
 import type { Shape } from 'lib/types/core.js';
 import type { SignedIdentityKeysBlob } from 'lib/types/crypto-types.js';
+import { isWebPlatform } from 'lib/types/device-types.js';
 import type { Platform, PlatformDetails } from 'lib/types/device-types.js';
 import type { CalendarQuery } from 'lib/types/entry-types.js';
 import {
@@ -317,7 +318,7 @@
     invariant(
       req.method === 'GET' ||
         viewer.sessionIdentifierType !== sessionIdentifierTypes.COOKIE_ID ||
-        viewer.platform !== 'web',
+        !isWebPlatform(viewer.platform),
       'non-GET request from web using sessionIdentifierTypes.COOKIE_ID',
     );
   }
diff --git a/lib/shared/message-utils.js b/lib/shared/message-utils.js
--- a/lib/shared/message-utils.js
+++ b/lib/shared/message-utils.js
@@ -11,7 +11,7 @@
 import { threadIsGroupChat } from './thread-utils.js';
 import { useStringForUser } from '../hooks/ens-cache.js';
 import { userIDsToRelativeUserInfos } from '../selectors/user-selectors.js';
-import type { PlatformDetails } from '../types/device-types.js';
+import { type PlatformDetails, isWebPlatform } from '../types/device-types.js';
 import type { Media } from '../types/media-types.js';
 import {
   type MessageInfo,
@@ -219,7 +219,7 @@
   rawMessageInfos: $ReadOnlyArray<RawMessageInfo>,
   platformDetails: ?PlatformDetails,
 ): RawMessageInfo[] {
-  if (platformDetails && platformDetails.platform === 'web') {
+  if (platformDetails && isWebPlatform(platformDetails.platform)) {
     return [...rawMessageInfos];
   }
   return rawMessageInfos.map(rawMessageInfo => {
diff --git a/lib/shared/version-utils.js b/lib/shared/version-utils.js
--- a/lib/shared/version-utils.js
+++ b/lib/shared/version-utils.js
@@ -1,12 +1,12 @@
 // @flow
 
-import type { PlatformDetails } from '../types/device-types.js';
+import { type PlatformDetails, isWebPlatform } from '../types/device-types.js';
 
 function hasMinCodeVersion(
   platformDetails: ?PlatformDetails,
   minCodeVersion: number,
 ): boolean {
-  if (!platformDetails || platformDetails.platform === 'web') {
+  if (!platformDetails || isWebPlatform(platformDetails.platform)) {
     return true;
   }
   const { codeVersion } = platformDetails;
diff --git a/lib/socket/socket.react.js b/lib/socket/socket.react.js
--- a/lib/socket/socket.react.js
+++ b/lib/socket/socket.react.js
@@ -29,6 +29,7 @@
   logInActionSources,
   type LogOutResult,
 } from '../types/account-types.js';
+import { isWebPlatform } from '../types/device-types.js';
 import type { CalendarQuery } from '../types/entry-types.js';
 import { forcePolicyAcknowledgmentActionType } from '../types/policy-types.js';
 import type { Dispatch } from '../types/redux-types.js';
@@ -120,8 +121,9 @@
   listeners: Set<SocketListener> = new Set();
   pingTimeoutID: ?TimeoutID;
   messageLastReceived: ?number;
-  initialPlatformDetailsSent: boolean =
-    getConfig().platformDetails.platform === 'web';
+  initialPlatformDetailsSent: boolean = isWebPlatform(
+    getConfig().platformDetails.platform,
+  );
   reopenConnectionAfterClosing: boolean = false;
   invalidationRecoveryInProgress: boolean = false;
   initializedWithUserState: ?PreRequestUserState;
@@ -130,7 +132,7 @@
   openSocket(newStatus: ConnectionStatus) {
     if (
       this.props.frozen ||
-      (getConfig().platformDetails.platform !== 'web' &&
+      (!isWebPlatform(getConfig().platformDetails.platform) &&
         (!this.props.cookie || !this.props.cookie.startsWith('user=')))
     ) {
       return;
diff --git a/lib/types/device-types.js b/lib/types/device-types.js
--- a/lib/types/device-types.js
+++ b/lib/types/device-types.js
@@ -17,6 +17,10 @@
   return deviceType;
 }
 
+export function isWebPlatform(platform: ?string): boolean {
+  return platform === 'web';
+}
+
 export type DeviceTokenUpdateRequest = {
   +deviceToken: string,
   +deviceType?: DeviceType,
diff --git a/lib/types/entry-types.js b/lib/types/entry-types.js
--- a/lib/types/entry-types.js
+++ b/lib/types/entry-types.js
@@ -1,6 +1,6 @@
 // @flow
 
-import type { Platform } from './device-types.js';
+import { type Platform, isWebPlatform } from './device-types.js';
 import { type CalendarFilter, defaultCalendarFilters } from './filter-types.js';
 import type { RawMessageInfo } from './message-types.js';
 import type {
@@ -56,7 +56,7 @@
   platform: ?Platform,
   timeZone?: ?string,
 ): CalendarQuery => {
-  if (platform === 'web') {
+  if (isWebPlatform(platform)) {
     return {
       ...thisMonthDates(timeZone),
       filters: defaultCalendarFilters,