diff --git a/static/js/directives/screenshare.js b/static/js/directives/screenshare.js
index 1eeb57c6..0eb8ae12 100644
--- a/static/js/directives/screenshare.js
+++ b/static/js/directives/screenshare.js
@@ -20,7 +20,7 @@
  */
 define(['jquery', 'underscore', 'text!partials/screenshare.html', 'text!partials/screensharepeer.html', 'bigscreen'], function($, _, template, templatePeer, BigScreen) {
 
-	return ["$window", "mediaStream", "$compile", "safeApply", "videoWaiter", "$timeout", "alertify", "translation", function($window, mediaStream, $compile, safeApply, videoWaiter, $timeout, alertify, translation) {
+	return ["$window", "mediaStream", "$compile", "safeApply", "videoWaiter", "$timeout", "alertify", "translation", "screensharing", function($window, mediaStream, $compile, safeApply, videoWaiter, $timeout, alertify, translation, screensharing) {
 
 		var peerTemplate = $compile(templatePeer);
 
@@ -168,9 +168,24 @@ define(['jquery', 'underscore', 'text!partials/screenshare.html', 'text!partials
 				}
 
 				$scope.layout.screenshare = true;
+				screensharing.getScreen().then(function(options) {
+					if (options) {
+						$scope.startScreenshare(options);
+					} else {
+						// No options received - assume cancel.
+						$scope.stopScreenshare();
+					}
+				}, function(err) {
+					console.log("Screen sharing request returned error", err);
+					$scope.stopScreenshare();
+				});
+
+			};
+
+			$scope.startScreenshare = function(options) {
 
 				// Create userMedia with screen share type.
-				var usermedia = mediaStream.webrtc.doScreenshare();
+				var usermedia = mediaStream.webrtc.doScreenshare(options);
 				var handler;
 				var peers = {};
 				var screenshares = [];
diff --git a/static/js/mediastream/peerscreenshare.js b/static/js/mediastream/peerscreenshare.js
index 6e6c3b20..824dc697 100644
--- a/static/js/mediastream/peerscreenshare.js
+++ b/static/js/mediastream/peerscreenshare.js
@@ -71,19 +71,16 @@ define(['jquery', 'underscore', 'mediastream/peercall', 'mediastream/tokens'], f
 		var screenWidth = window.screen.width;
 		var screenHeight = window.screen.height;
 
-		// NOTE(longsleep): This generates constrains for the experiental Screen sharing
-		// support in Chrome 31+. This needs to be enabled in flags:
-		// chrome://flags/#enable-usermedia-screen-capture
+		// Constains which define what actually gets shared need to
+		// be provided in options.
 		var mandatoryVideoConstraints = $.extend({
-			chromeMediaSource: 'screen',
 			maxWidth: screenWidth,
 			maxHeight: screenHeight
 		}, options);
 		var mediaConstraints = {
 			audio: false,
 			video: {
-				mandatory: mandatoryVideoConstraints,
-				optional: []
+				mandatory: mandatoryVideoConstraints
 			}
 		}
 		console.log("Setting screen sharing media constraints", mandatoryVideoConstraints);
diff --git a/static/js/mediastream/webrtc.js b/static/js/mediastream/webrtc.js
index 9ba200b1..bfe13ec8 100644
--- a/static/js/mediastream/webrtc.js
+++ b/static/js/mediastream/webrtc.js
@@ -481,7 +481,7 @@ function($, _, PeerCall, PeerConference, PeerXfer, PeerScreenshare, UserMedia, u
 		var usermedia = new UserMedia({
 			noaudio: true
 		});
-		var ok = usermedia.doGetUserMedia(null, PeerScreenshare.getMediaContraints());
+		var ok = usermedia.doGetUserMedia(null, PeerScreenshare.getMediaContraints(options));
 		if (ok) {
 			this.e.one("done", function() {
 				usermedia.stop();
diff --git a/static/js/services/chromeextension.js b/static/js/services/chromeextension.js
new file mode 100644
index 00000000..532c8909
--- /dev/null
+++ b/static/js/services/chromeextension.js
@@ -0,0 +1,100 @@
+/*
+ * Spreed WebRTC.
+ * Copyright (C) 2013-2014 struktur AG
+ *
+ * This file is part of Spreed WebRTC.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+define(["underscore"], function(_) {
+
+	// chromeExtension
+	return ["$window", "$q", function($window, $q) {
+
+		var available = false;
+		var marker = $window.document.getElementById("chromeextension-available");
+		if (marker) {
+			available = true;
+			console.log("Chrome extension is available.");
+		}
+
+		var ChromeExtension = function() {
+			this.registry = {};
+			this.count = 0;
+		};
+
+		ChromeExtension.prototype.call = function(data) {
+			var deferred = $q.defer();
+			var n = this.count++;
+			this.registry[n] = deferred;
+			var msg = {
+				Type: "Call",
+				Call: data,
+				n: n
+			}
+			$window.postMessage(msg, $window.document.URL);
+			return deferred.promise;
+		};
+
+		ChromeExtension.prototype.onMessage = function(event) {
+			var data = event.data;
+			switch (data.Type) {
+			case "Call":
+				var deferred = this.registry[data.n];
+				if (deferred) {
+					delete this.registry[data.n];
+					var call = data.Call;
+					if (call.Type === "Result") {
+						//console.log("Call complete with result", call);
+						deferred.resolve(call.Result);
+					} else {
+						//console.log("Call failed with error", call);
+						deferred.reject(call.Error);
+					}
+				} else {
+					console.warn("Unknown call reference received", data, this.registry, this);
+				}
+				break;
+			default:
+				console.log("Unknown message type", data.Type, data);
+				break;
+			}
+		};
+
+		var extension;
+		if (available) {
+			extension = new ChromeExtension();
+
+			$window.addEventListener("message", function(event) {
+				//console.log("message", event.origin, event.source === window, event);
+				if (event.source === window && event.data.answer) {
+					// Only let through our own messages marked as answer.
+					extension.onMessage(event);
+				}
+			});
+
+		}
+
+		// public API.
+		return {
+			available: available,
+			call: function(data) {
+				return extension.call(data);
+			}
+		}
+
+	}];
+
+});
\ No newline at end of file
diff --git a/static/js/services/screensharing.js b/static/js/services/screensharing.js
index e5500677..1c0341b0 100644
--- a/static/js/services/screensharing.js
+++ b/static/js/services/screensharing.js
@@ -18,13 +18,14 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
-define(['webrtc.adapter'], function() {
+define(['underscore', 'webrtc.adapter'], function(_) {
 
 	// screensharing
-	return ["$window", function($window) {
+	return ["$window", "$q", "chromeExtension", function($window, $q, chromeExtension) {
 
 		// Check if we can do screensharing.
 		var supported = false;
+		var prepare = null;
 		if ($window.webrtcDetectedBrowser === "chrome") {
 			if ($window.webrtcDetectedVersion >= 32 &&
 				$window.webrtcDetectedVersion < 37) {
@@ -32,18 +33,66 @@ define(['webrtc.adapter'], function() {
 				// It was removed in Chrome 37 in favour of chrome.chooseDesktopMedia
 				// https://code.google.com/p/chromium/issues/detail?id=347641
 				supported = true;
+				prepare = function(options) {
+					// This generates constrains for the flag based screen screensharing
+					// support in Chrome 31+ to 36. Flag to be enabled is found at:
+					// chrome://flags/#enable-usermedia-screen-capture
+					var d = $q.defer()
+					var opts = _.extend({
+						chromeMediaSource: "screen"
+					}, options);
+					d.resolve(opts);
+					return d.promise;
+				};
 			} else if ($window.webrtcDetectedVersion >= 37) {
 				// We need a extension to support screen sharing. See
 				// https://developer.chrome.com/extensions/desktopCapture#method-chooseDesktopMedia
 				// for details.
 			}
+
+			if (chromeExtension.available) {
+				supported = true;
+				prepare = function(options) {
+					var select = chromeExtension.call({
+						Type: "Action",
+						Action: "chooseDesktopMedia"
+					});
+					var d = $q.defer();
+					select.then(function(id) {
+						//console.log("Prepare screensharing success", id);
+						if (id) {
+							var opts = _.extend({
+								chromeMediaSource: "desktop",
+								chromeMediaSourceId: id
+							}, options);
+							d.resolve(opts);
+						} else {
+							d.resolve(null);
+						}
+					}, function(err) {
+						console.log("Failed to prepare screensharing", err);
+						d.reject(err);
+					});
+					return d.promise;
+				};
+			}
+
 		} else {
 			// Currently Chrome only.
 		}
 
 		// public API.
 		return {
-			supported: supported
+			supported: supported,
+			getScreen: function(options) {
+				if (prepare) {
+					return prepare(options);
+				} else {
+					var d = $q.defer()
+					d.reject("No implementation to get screen.");
+					return d.promise;
+				}
+			}
 		}
 
 	}];
diff --git a/static/js/services/services.js b/static/js/services/services.js
index f29f9e97..597a26cf 100644
--- a/static/js/services/services.js
+++ b/static/js/services/services.js
@@ -53,7 +53,8 @@ define([
 	'services/dialogs',
 	'services/geolocation',
 	'services/screensharing',
-	'services/continueconnector'], function(_,
+	'services/continueconnector',
+	'services/chromeextension'], function(_,
 desktopNotify,
 playSound,
 safeApply,
@@ -86,7 +87,8 @@ animationFrame,
 dialogs,
 geolocation,
 screensharing,
-continueConnector) {
+continueConnector,
+chromeExtension) {
 
 	var services = {
 		desktopNotify: desktopNotify,
@@ -121,7 +123,8 @@ continueConnector) {
 		dialogs: dialogs,
 		geolocation: geolocation,
 		screensharing: screensharing,
-		continueConnector: continueConnector
+		continueConnector: continueConnector,
+		chromeExtension: chromeExtension
 	};
 
 	var initialize = function(angModule) {