diff --git a/syweb/webclient/components/matrix/matrix-call.js b/syweb/webclient/components/matrix/matrix-call.js
index 465b2b7807..c13083298e 100644
--- a/syweb/webclient/components/matrix/matrix-call.js
+++ b/syweb/webclient/components/matrix/matrix-call.js
@@ -40,14 +40,11 @@ window.RTCPeerConnection = window.RTCPeerConnection || window.webkitRTCPeerConne
 window.RTCSessionDescription = window.RTCSessionDescription || window.webkitRTCSessionDescription || window.mozRTCSessionDescription;
 window.RTCIceCandidate = window.RTCIceCandidate || window.webkitRTCIceCandidate || window.mozRTCIceCandidate;
 
-// Returns true if the browser supports all required features to make WebRTC call
-var isWebRTCSupported = function () {
-    return !!(navigator.getUserMedia || window.RTCPeerConnection || window.RTCSessionDescription || window.RTCIceCandidate);
-};
-
 angular.module('MatrixCall', [])
 .factory('MatrixCall', ['matrixService', 'matrixPhoneService', 'modelService', '$rootScope', '$timeout', function MatrixCallFactory(matrixService, matrixPhoneService, modelService, $rootScope, $timeout) {
-    $rootScope.isWebRTCSupported = isWebRTCSupported();
+    $rootScope.isWebRTCSupported = function () {
+        return !!(navigator.getUserMedia || window.RTCPeerConnection || window.RTCSessionDescription || window.RTCIceCandidate);
+    };
 
     var MatrixCall = function(room_id) {
         this.room_id = room_id;
diff --git a/syweb/webclient/components/matrix/matrix-phone-service.js b/syweb/webclient/components/matrix/matrix-phone-service.js
index 06465ed821..55dbbf522e 100644
--- a/syweb/webclient/components/matrix/matrix-phone-service.js
+++ b/syweb/webclient/components/matrix/matrix-phone-service.js
@@ -60,7 +60,7 @@ angular.module('matrixPhoneService', [])
             var MatrixCall = $injector.get('MatrixCall');
             var call = new MatrixCall(event.room_id);
 
-            if (!isWebRTCSupported()) {
+            if (!$rootScope.isWebRTCSupported()) {
                 console.log("Incoming call ID "+msg.call_id+" but this browser doesn't support WebRTC");
                 // don't hang up the call: there could be other clients connected that do support WebRTC and declining the
                 // the call on their behalf would be really annoying.
diff --git a/syweb/webclient/index.html b/syweb/webclient/index.html
index 3ed968a5ea..992e8d3377 100644
--- a/syweb/webclient/index.html
+++ b/syweb/webclient/index.html
@@ -85,7 +85,7 @@
                     </span>
                 </div>
                 <span ng-show="currentCall.state == 'ringing'">
-                    <button ng-click="answerCall()" ng-disabled="!isWebRTCSupported" title="{{isWebRTCSupported ? '' : 'Your browser does not support VoIP' }}">Answer {{ currentCall.type }} call</button>
+                    <button ng-click="answerCall()" ng-disabled="!isWebRTCSupported()" title="{{isWebRTCSupported() ? '' : 'Your browser does not support VoIP' }}">Answer {{ currentCall.type }} call</button>
                     <button ng-click="hangupCall()">Reject</button>
                 </span>
                 <button ng-click="hangupCall()" ng-show="currentCall && currentCall.state != 'ringing' && currentCall.state != 'ended' && currentCall.state != 'fledgling'">Hang up</button>
diff --git a/syweb/webclient/room/room.html b/syweb/webclient/room/room.html
index ca5669a732..e59cc30edc 100644
--- a/syweb/webclient/room/room.html
+++ b/syweb/webclient/room/room.html
@@ -182,8 +182,8 @@
                                                                                         (msg.content.formatted_body | unsanitizedLinky) :
                                              (msg.content.msgtype === 'm.text' && msg.type === 'm.room.message') ? (msg.content.body | linky:'_blank') : '' "/>
 
-                        <span ng-show='msg.type === "m.call.invite" && msg.user_id == state.user_id'>Outgoing Call{{ isWebRTCSupported ? '' : ' (But your browser does not support VoIP)' }}</span>
-                        <span ng-show='msg.type === "m.call.invite" && msg.user_id != state.user_id'>Incoming Call{{ isWebRTCSupported ? '' : ' (But your browser does not support VoIP)' }}</span>
+                        <span ng-show='msg.type === "m.call.invite" && msg.user_id == state.user_id'>Outgoing Call{{ isWebRTCSupported() ? '' : ' (But your browser does not support VoIP)' }}</span>
+                        <span ng-show='msg.type === "m.call.invite" && msg.user_id != state.user_id'>Incoming Call{{ isWebRTCSupported() ? '' : ' (But your browser does not support VoIP)' }}</span>
 
                         <div ng-show='msg.content.msgtype === "m.image"'>
                             <div ng-hide='msg.content.thumbnail_url' ng-style="msg.content.body.h && { 'height' : (msg.content.body.h < 320) ? msg.content.body.h : 320}">
@@ -248,15 +248,15 @@
                 <button ng-click="leaveRoom()" ng-disabled="state.permission_denied">Leave</button>
                 <button ng-click="startVoiceCall()"
                         ng-show="(currentCall == undefined || currentCall.state == 'ended')"
-                        ng-disabled="state.permission_denied || !isWebRTCSupported || memberCount() != 2"
-                        title ="{{ !isWebRTCSupported ? 'VoIP requires webRTC but your browser does not support it' : (memberCount() == 2 ? '' : 'VoIP calls can only be made in rooms with two participants') }}"
+                        ng-disabled="state.permission_denied || !isWebRTCSupported() || memberCount() != 2"
+                        title ="{{ !isWebRTCSupported() ? 'VoIP requires webRTC but your browser does not support it' : (memberCount() == 2 ? '' : 'VoIP calls can only be made in rooms with two participants') }}"
                         >
                     Voice Call
                 </button>
                 <button ng-click="startVideoCall()"
                         ng-show="(currentCall == undefined || currentCall.state == 'ended')"
-                        ng-disabled="state.permission_denied || !isWebRTCSupported || memberCount() != 2"
-                        title ="{{ !isWebRTCSupported ? 'VoIP requires webRTC but your browser does not support it' : (memberCount() == 2 ? '' : 'VoIP calls can only be made in rooms with two participants') }}"
+                        ng-disabled="state.permission_denied || !isWebRTCSupported() || memberCount() != 2"
+                        title ="{{ !isWebRTCSupported() ? 'VoIP requires webRTC but your browser does not support it' : (memberCount() == 2 ? '' : 'VoIP calls can only be made in rooms with two participants') }}"
                         >
                     Video Call
                 </button>