diff --git a/lib/webrtc/call.js b/lib/webrtc/call.js
index 0092fc8ec..0cb17f39b 100644
--- a/lib/webrtc/call.js
+++ b/lib/webrtc/call.js
@@ -92,6 +92,8 @@ MatrixCall.prototype.placeVideoCall = function(remoteVideoElement, localVideoEle
 
 /**
  * Place a screen-sharing call to this room. This includes audio.
+ * <b>This method is EXPERIMENTAL and subject to change without warning. It
+ * only works in Google Chrome.</b>
  * @param {Element} remoteVideoElement a <code>&lt;video&gt;</code> DOM element
  * to render video to.
  * @param {Element} localVideoElement a <code>&lt;video&gt;</code> DOM element