diff --git a/src/api/gramjs/methods/client.ts b/src/api/gramjs/methods/client.ts
index a5216d182..3a0029c19 100644
--- a/src/api/gramjs/methods/client.ts
+++ b/src/api/gramjs/methods/client.ts
@@ -45,7 +45,7 @@ export async function init(_onUpdate: OnApiUpdate, initialArgs: ApiInitialArgs)
   onUpdate = _onUpdate;
 
   const {
-    userAgent, platform, sessionData, isMovSupported,
+    userAgent, platform, sessionData, isTest, isMovSupported,
   } = initialArgs;
   const session = new sessions.CallbackSession(sessionData, onSessionUpdate);
 
@@ -61,6 +61,7 @@ export async function init(_onUpdate: OnApiUpdate, initialArgs: ApiInitialArgs)
       appVersion: `${APP_VERSION} ${APP_CODE_NAME}`,
       useWSS: true,
       additionalDcsDisabled: IS_TEST,
+      testServers: isTest,
     } as any,
   );
 
diff --git a/src/api/types/misc.ts b/src/api/types/misc.ts
index 310e8c4c6..7bc61f43b 100644
--- a/src/api/types/misc.ts
+++ b/src/api/types/misc.ts
@@ -4,6 +4,7 @@ export interface ApiInitialArgs {
   userAgent: string;
   platform?: string;
   sessionData?: ApiSessionData;
+  isTest?: boolean;
   isMovSupported?: boolean;
 }
 
diff --git a/src/hooks/useHistoryBack.ts b/src/hooks/useHistoryBack.ts
index 9b82a0767..26aa318c0 100644
--- a/src/hooks/useHistoryBack.ts
+++ b/src/hooks/useHistoryBack.ts
@@ -5,12 +5,6 @@ import usePrevious from './usePrevious';
 import { getDispatch } from '../lib/teact/teactn';
 import { areSortedArraysEqual } from '../util/iteratees';
 
-// Carefully selected by swiping and observing visual changes
-// TODO: may be different on other devices such as iPad, maybe take dpi into account?
-const SAFARI_EDGE_BACK_GESTURE_LIMIT = 300;
-const SAFARI_EDGE_BACK_GESTURE_DURATION = 350;
-export const LOCATION_HASH = window.location.hash;
-
 type HistoryState = {
   currentIndex: number;
   nextStateIndexToReplace: number;
@@ -20,6 +14,13 @@ type HistoryState = {
   currentIndexes: number[];
 };
 
+// Carefully selected by swiping and observing visual changes
+// TODO: may be different on other devices such as iPad, maybe take dpi into account?
+const SAFARI_EDGE_BACK_GESTURE_LIMIT = 300;
+const SAFARI_EDGE_BACK_GESTURE_DURATION = 350;
+export const LOCATION_HASH = window.location.hash;
+const PATH_BASE = `${window.location.pathname}${window.location.search}`;
+
 const historyState: HistoryState = {
   currentIndex: 0,
   nextStateIndexToReplace: -1,
@@ -55,7 +56,7 @@ if (IS_IOS) {
   window.addEventListener('popstate', handleTouchEnd);
 }
 
-window.history.replaceState({ index: historyState.currentIndex }, '', window.location.pathname);
+window.history.replaceState({ index: historyState.currentIndex }, '', PATH_BASE);
 
 export default function useHistoryBack(
   isActive: boolean | undefined,
@@ -87,14 +88,16 @@ export default function useHistoryBack(
 
             historyState.currentIndexes.push(index);
 
-            window.history[
-              (historyState.currentIndexes.includes(historyState.nextStateIndexToReplace - 1)
+            window.history[(
+              (
+                historyState.currentIndexes.includes(historyState.nextStateIndexToReplace - 1)
                 && window.history.state.index !== 0
                 && historyState.nextStateIndexToReplace === index
-                && !shouldReplaceNext)
+                && !shouldReplaceNext
+              )
                 ? 'replaceState'
                 : 'pushState'
-            ]({
+            )]({
               index,
               state: currentState,
             }, '');
@@ -170,7 +173,7 @@ export default function useHistoryBack(
               window.history.replaceState({
                 index,
                 state: currentState,
-              }, '', `#${hashes[hashes.length - 1]}`);
+              }, '', `${PATH_BASE}#${hashes[hashes.length - 1]}`);
 
               indexHashRef.current[indexHashRef.current.length - 1] = {
                 index,
diff --git a/src/lib/gramjs/client/TelegramClient.js b/src/lib/gramjs/client/TelegramClient.js
index 1e83b75eb..217080818 100644
--- a/src/lib/gramjs/client/TelegramClient.js
+++ b/src/lib/gramjs/client/TelegramClient.js
@@ -38,7 +38,6 @@ const PING_DISCONNECT_DELAY = 60000; // 1 min
 // All types
 const sizeTypes = ['w', 'y', 'd', 'x', 'c', 'm', 'b', 'a', 's'];
 
-
 class TelegramClient {
     static DEFAULT_OPTIONS = {
         connection: ConnectionTCPObfuscated,
@@ -59,6 +58,7 @@ class TelegramClient {
         baseLogger: 'gramjs',
         useWSS: false,
         additionalDcsDisabled: false,
+        testServers: false,
     };
 
     /**
@@ -148,7 +148,6 @@ class TelegramClient {
         this._destroyed = false;
     }
 
-
     // region Connecting
 
     /**
@@ -181,7 +180,7 @@ class TelegramClient {
         this._sender._disconnected = true;
 
         const connection = new this._connection(
-            this.session.serverAddress, this.session.port, this.session.dcId, this._log,
+            this.session.serverAddress, this.session.port, this.session.dcId, this._log, this._args.testServers,
         );
 
         const newConnection = await this._sender.connect(connection);
@@ -337,6 +336,7 @@ class TelegramClient {
                     dc.port,
                     dcId,
                     this._log,
+                    this._args.testServers,
                 ));
 
                 if (this.session.dcId !== dcId && !sender._authenticated) {
@@ -551,7 +551,6 @@ class TelegramClient {
         return undefined;
     }
 
-
     _downloadCachedPhotoSize(size) {
         // No need to download anything, simply write the bytes
         let data;
@@ -688,7 +687,6 @@ class TelegramClient {
         // This causes issues for now because not enough utils
         // await request.resolve(this, utils)
 
-
         this._lastRequest = new Date().getTime();
         let attempt = 0;
         for (attempt = 0; attempt < this._requestRetries; attempt++) {
@@ -800,7 +798,6 @@ class TelegramClient {
         this._dispatchUpdate(args);
     }
 
-
     // endregion
 
     // region private methods
@@ -883,7 +880,6 @@ class TelegramClient {
     */
     // endregion
 
-
     // users region
     /**
      Turns the given entity into its input entity version.
@@ -1067,6 +1063,7 @@ async function attempts(cb, times, pause) {
     for (let i = 0; i < times; i++) {
         try {
             // We need to `return await` here so it can be caught locally
+            // eslint-disable-next-line no-return-await
             return await cb();
         } catch (err) {
             if (i === times - 1) {
diff --git a/src/lib/gramjs/crypto/RSA.ts b/src/lib/gramjs/crypto/RSA.ts
index a08836761..7b73554d2 100644
--- a/src/lib/gramjs/crypto/RSA.ts
+++ b/src/lib/gramjs/crypto/RSA.ts
@@ -20,6 +20,18 @@ const PUBLIC_KEYS = [
         ),
         e: 65537,
     },
+    {
+        fingerprint: bigInt('-5595554452916591101'),
+        n: bigInt(
+            '2534288944884041556497168959071347320689884775908477905258202659454602246385394058588521595116849196570822' +
+            '26493991806038180742006204637761354248846321625124031637930839216416315647409595294193595958529411668489405859523' +
+            '37613333022396096584117954892216031229237302943701877588456738335398602461675225081791820393153757504952636234951' +
+            '32323782003654358104782690612092797248736680529211579223142368426126233039432475078545094258975175539015664775146' +
+            '07193514399690599495696153028090507215003302390050778898553239175099482557220816446894421272976054225797071426466' +
+            '60768825302832201908302295573257427896031830742328565032949',
+        ),
+        e: 65537,
+    },
 ];
 
 export const _serverKeys = new Map<string, { n: bigInt.BigInteger; e: number }>();
diff --git a/src/lib/gramjs/extensions/PromisedWebSockets.js b/src/lib/gramjs/extensions/PromisedWebSockets.js
index fe880391a..8c6a65736 100644
--- a/src/lib/gramjs/extensions/PromisedWebSockets.js
+++ b/src/lib/gramjs/extensions/PromisedWebSockets.js
@@ -65,21 +65,21 @@ class PromisedWebSockets {
         return toReturn;
     }
 
-    getWebSocketLink(ip, port) {
+    getWebSocketLink(ip, port, testServers) {
         if (port === 443) {
-            return `wss://${ip}:${port}/apiws`;
+            return `wss://${ip}:${port}/apiws${testServers ? '_test' : ''}`;
         } else {
-            return `ws://${ip}:${port}/apiws`;
+            return `ws://${ip}:${port}/apiws${testServers ? '_test' : ''}`;
         }
     }
 
-    connect(port, ip) {
+    connect(port, ip, testServers = false) {
         this.stream = Buffer.alloc(0);
         this.canRead = new Promise((resolve) => {
             this.resolveRead = resolve;
         });
         this.closed = false;
-        this.website = this.getWebSocketLink(ip, port);
+        this.website = this.getWebSocketLink(ip, port, testServers);
         this.client = new WebSocketClient(this.website, 'binary');
         return new Promise((resolve, reject) => {
             this.client.onopen = () => {
diff --git a/src/lib/gramjs/network/MTProtoSender.js b/src/lib/gramjs/network/MTProtoSender.js
index b78adbaf8..6738cde27 100644
--- a/src/lib/gramjs/network/MTProtoSender.js
+++ b/src/lib/gramjs/network/MTProtoSender.js
@@ -844,6 +844,7 @@ class MTProtoSender {
             this._connection._port,
             this._connection._dcId,
             this._connection._log,
+            this._connection._testServers,
         );
         await this.connect(newConnection, true);
 
diff --git a/src/lib/gramjs/network/connection/Connection.js b/src/lib/gramjs/network/connection/Connection.js
index 29264f485..cce174dd9 100644
--- a/src/lib/gramjs/network/connection/Connection.js
+++ b/src/lib/gramjs/network/connection/Connection.js
@@ -15,11 +15,12 @@ const AsyncQueue = require('../../extensions/AsyncQueue');
 class Connection {
     PacketCodecClass = undefined;
 
-    constructor(ip, port, dcId, loggers) {
+    constructor(ip, port, dcId, loggers, testServers) {
         this._ip = ip;
         this._port = port;
         this._dcId = dcId;
         this._log = loggers;
+        this._testServers = testServers;
         this._connected = false;
         this._sendTask = undefined;
         this._recvTask = undefined;
@@ -39,7 +40,7 @@ class Connection {
     async _connect() {
         this._log.debug('Connecting');
         this._codec = new this.PacketCodecClass(this);
-        await this.socket.connect(this._port, this._ip, this);
+        await this.socket.connect(this._port, this._ip, this._testServers);
         this._log.debug('Finished connecting');
         // await this.socket.connect({host: this._ip, port: this._port});
         await this._initConn();
@@ -152,7 +153,6 @@ class ObfuscatedConnection extends Connection {
         this._obfuscation.write(this._codec.encodePacket(data));
     }
 
-
     _recv() {
         return this._codec.readPacket(this._obfuscation);
     }
diff --git a/src/modules/actions/api/initial.ts b/src/modules/actions/api/initial.ts
index 3af30b5f3..719ce42e4 100644
--- a/src/modules/actions/api/initial.ts
+++ b/src/modules/actions/api/initial.ts
@@ -37,6 +37,7 @@ addReducer('initApi', (global: GlobalState, actions) => {
       userAgent: navigator.userAgent,
       platform: PLATFORM_ENV,
       sessionData: loadStoredSession(),
+      isTest: window.location.search.includes('test'),
       isMovSupported: IS_MOV_SUPPORTED,
     });
   })();