diff --git a/.flowconfig b/.flowconfig
index 0f497fc2..ea6ba31f 100644
--- a/.flowconfig
+++ b/.flowconfig
@@ -6,6 +6,7 @@
 .*/node_modules/redux/.*
 .*/node_modules/react-router/.*
 .*/node_modules/react-router-redux/.*
+.*/node_modules/trezor-connect/.*
 .*/_old/.*
 .*/src/solidity/.*
 
diff --git a/src/flowtype/trezor-connect.js b/src/flowtype/trezor-connect.js
index cb13d712..d8f89b29 100644
--- a/src/flowtype/trezor-connect.js
+++ b/src/flowtype/trezor-connect.js
@@ -32,6 +32,7 @@ declare module 'trezor-connect' {
 
     declare type T_UI_EVENT = 'UI_EVENT';
     declare type T_UI = {
+        IFRAME_HANDSHAKE: 'iframe_handshake',
         TRANSPORT: 'ui-no_transport',
         BOOTLOADER: 'ui-device_bootloader_mode',
         INITIALIZE: 'ui-device_not_initialized',
@@ -96,6 +97,7 @@ declare module 'trezor-connect' {
         payload: {
             device: Device;
             code?: string;
+            browser?: any;
         }
     }
     
diff --git a/src/js/reducers/TrezorConnectReducer.js b/src/js/reducers/TrezorConnectReducer.js
index 7c750f0b..c112c580 100644
--- a/src/js/reducers/TrezorConnectReducer.js
+++ b/src/js/reducers/TrezorConnectReducer.js
@@ -1,7 +1,7 @@
 /* @flow */
 'use strict';
 
-import { TRANSPORT, DEVICE } from 'trezor-connect';
+import { TRANSPORT, DEVICE, UI } from 'trezor-connect';
 import * as CONNECT from '../actions/constants/TrezorConnect';
 import * as WALLET from '../actions/constants/wallet';
 
@@ -50,8 +50,7 @@ export default function connect(state: State = initialState, action: Action): St
 
     switch (action.type) {
 
-        // TODO: change it to UiMessage from trezor-connect
-        case 'iframe_handshake' : 
+        case UI.IFRAME_HANDSHAKE : 
             return {
                 ...state,
                 browserState: action.payload.browser