diff --git a/lib/client.js b/lib/client.js
index 63fc27959..44365c500 100644
--- a/lib/client.js
+++ b/lib/client.js
@@ -1393,17 +1393,21 @@ MatrixClient.prototype.setAvatarUrl = function(url, callback) {
  * @param {Number} height The desired height of the thumbnail.
  * @param {string} resizeMethod The thumbnail resize method to use, either
  * "crop" or "scale".
+ * @param {Boolean} allowDefault (optional) Passing false causes this method to
+ * return null if the user has no avatar image. Otherwise, a default image URL
+ * will be returned.
  * @return {?string} the avatar URL or null.
  */
 MatrixClient.prototype.getAvatarUrlForMember =
-        function(member, width, height, resizeMethod) {
+        function(member, width, height, resizeMethod, allowDefault) {
     if (!member || !member.events.member) {
         return null;
     }
+    if (allowDefault === undefined) { allowDefault = true; }
     var rawUrl = member.events.member.getContent().avatar_url;
     if (rawUrl) {
         return this._http.getHttpUriForMxc(rawUrl, width, height, resizeMethod);
-    } else {
+    } else if (allowDefault) {
         return this._http.getIdenticonUri(member.userId, width, height);
     }
     return null;