diff --git a/static/js/services/screensharing.js b/static/js/services/screensharing.js
index 722b7bc4..5a5f572b 100644
--- a/static/js/services/screensharing.js
+++ b/static/js/services/screensharing.js
@@ -20,10 +20,22 @@
  */
 
 "use strict";
-define(['underscore', 'webrtc.adapter'], function(_) {
+define(['underscore', 'text!partials/screensharedialogff.html', 'webrtc.adapter'], function(_, screenshareDialogFF) {
+
+	var screenshareDialogFFController = ["$scope", "$modalInstance", "data", function($scope, $modalInstance, data) {
+		$scope.data = data;
+		$scope.cancel = function() {
+			$modalInstance.close(null);
+		};
+		$scope.ok = function() {
+			$modalInstance.close($scope.data.selection);
+		};
+	}];
 
 	// screensharing
-	return ["$window", "$q", "$timeout", "chromeExtension", function($window, $q, $timeout, chromeExtension) {
+	return ["$window", "$q", "$timeout", "chromeExtension", "dialogs", "$templateCache", function($window, $q, $timeout, chromeExtension, dialogs, $templateCache) {
+
+		$templateCache.put('/dialogs/screensharedialogff.html', screenshareDialogFF);
 
 		var Screensharing = function() {
 			this.autoinstall = false;
@@ -131,11 +143,20 @@ define(['underscore', 'webrtc.adapter'], function(_) {
 						// To work, the current domain must be whitelisted in
 						// media.getusermedia.screensharing.allowed_domains (about:config).
 						// See https://wiki.mozilla.org/Screensharing for reference.
-						var d = $q.defer()
-						var opts = _.extend({
-							mediaSource: "screen"
-						}, options);
-						d.resolve(opts);
+						var d = $q.defer();
+						var dlg = dialogs.create('/dialogs/screensharedialogff.html', screenshareDialogFFController, {selection: "screen"}, {});
+						dlg.result.then(function(source) {
+							if (source) {
+								var opts = _.extend({
+									mediaSource: source
+								}, options);
+								d.resolve(opts);
+							} else {
+								d.resolve(null);
+							}
+						}, function(err) {
+							d.resolve(null);
+						});
 						return d.promise;
 					};
 				}
diff --git a/static/partials/screensharedialogff.html b/static/partials/screensharedialogff.html
new file mode 100644
index 00000000..86a56687
--- /dev/null
+++ b/static/partials/screensharedialogff.html
@@ -0,0 +1,22 @@
+<div>
+	<div class="modal-header"><button type="button" class="close" ng-click="$close()">×</button><h3 class="modal-title">{{_("Share screen")}}</h3></div>
+	<div class="modal-body">
+		<ng-form name="promptDialog" novalidate role="form">
+			<h4>{{_("Please select what to share.")}}</h4>
+			<div class="btn-group">
+				<label class="btn btn-default" ng-model="data.selection" btn-radio="'screen'">{{_("Screen")}}</label>
+				<label class="btn btn-default" ng-model="data.selection" btn-radio="'window'">{{_("Window")}}</label>
+				<label class="btn btn-default" ng-model="data.selection" btn-radio="'application'">{{_("Application")}}</label>
+			</div>
+			<div ng-switch="data.selection">
+				<span class="help-block" ng-switch-when="screen">Share the whole screen. Click share to select the screen.</span>
+				<span class="help-block" ng-switch-when="window">Share a single window. Click share to select the window.</span>
+				<span class="help-block" ng-switch-when="application">Share all windows of a application. This can leak content behind windows when windows get moved. Click share to select the application.</span>
+			</div>
+		</ng-form>
+	</div>
+	<div class="modal-footer">
+		<button type="button" class="btn btn-default" ng-click="cancel()">{{_("Cancel")}}</button>
+		<button type="button" class="btn btn-primary" ng-click="ok()" ng-disabled="(promptDialog.$dirty && promptDialog.$invalid) || !data.selection">{{_("Share")}}</button>
+	</div>
+</div>
\ No newline at end of file