diff --git a/packages/livedata/livedata_server.js b/packages/livedata/livedata_server.js
index 0b42d9a3e8..38edb50fc1 100644
--- a/packages/livedata/livedata_server.js
+++ b/packages/livedata/livedata_server.js
@@ -266,6 +266,8 @@ if (typeof Meteor === "undefined") Meteor = {};
         if (arguments.length === 0)
           selector = {};
 
+        // XXX when implementing observe() on the server, either
+        // support limit or remove this performance hack.
         options = options || {};
         options.limit = 1;
         return this.find(selector, options).fetch()[0];
diff --git a/packages/minimongo/minimongo.js b/packages/minimongo/minimongo.js
index 3445a23c58..61c144c1e8 100644
--- a/packages/minimongo/minimongo.js
+++ b/packages/minimongo/minimongo.js
@@ -81,8 +81,10 @@ Collection.prototype.findOne = function (selector, options) {
   if (arguments.length === 0)
     selector = {};
 
-  options = options || {};
-  options.limit = 1;
+  // XXX disable limit here so that we can observe findOne() cursor,
+  // as required by markAsReactive.
+  // options = options || {};
+  // options.limit = 1;
   return this.find(selector, options).fetch()[0];
 };