diff --git a/packages/meteor/fiber_helpers.js b/packages/meteor/fiber_helpers.js
index e1b0778c31..9d0ce4180d 100644
--- a/packages/meteor/fiber_helpers.js
+++ b/packages/meteor/fiber_helpers.js
@@ -52,6 +52,11 @@ Meteor._SynchronousQueue = function () {
   // that task. We use this to throw an error rather than deadlocking if the
   // user calls runTask from within a task on the same fiber.
   self._currentTaskFiber = undefined;
+  // This is true if we're currently draining.  While we're draining, a further
+  // drain is a noop, to prevent infinite loops.  "drain" is a heuristic type
+  // operation, that has a meaning like unto "what a naive person would expect
+  // when modifying a table from an observe"
+  self._draining = false;
 };
 
 _.extend(Meteor._SynchronousQueue.prototype, {
@@ -91,11 +96,15 @@ _.extend(Meteor._SynchronousQueue.prototype, {
 
   drain: function () {
     var self = this;
+    if (self._draining)
+      return;
     if (!self.safeToRunTask())
       return;
+    self._draining = true;
     while (!_.isEmpty(self._taskHandles)) {
       self.flush();
     }
+    self._draining = false;
   },
 
   _scheduleRun: function () {