diff --git a/History.md b/History.md
index e976580608..b74782128a 100644
--- a/History.md
+++ b/History.md
@@ -1,5 +1,6 @@
 ## v.NEXT
 
+* Fix stack trace when a browser tries to use the server like a proxy.  #1212
 
 ## v1.0.2.1, 2014-Dec-22
 
diff --git a/packages/routepolicy/routepolicy.js b/packages/routepolicy/routepolicy.js
index e426f6ac37..81e47c64c0 100644
--- a/packages/routepolicy/routepolicy.js
+++ b/packages/routepolicy/routepolicy.js
@@ -97,6 +97,10 @@ _.extend(RoutePolicyConstructor.prototype, {
     self.urlPrefixTypes[urlPrefix] = type;
   },
 
+  isValidUrl: function (url) {
+    return url.charAt(0) === '/';
+  },
+
   classify: function (url) {
     var self = this;
     if (url.charAt(0) !== '/')
diff --git a/packages/webapp/webapp_server.js b/packages/webapp/webapp_server.js
index 422357e33b..b5bd652d0e 100644
--- a/packages/webapp/webapp_server.js
+++ b/packages/webapp/webapp_server.js
@@ -565,6 +565,18 @@ var runWebAppServer = function () {
   var rawConnectHandlers = connect();
   app.use(rawConnectHandlers);
 
+  // We're not a proxy; reject (without crashing) attempts to treat us like
+  // one. (See #1212.)
+  app.use(function(req, res, next) {
+    if (RoutePolicy.isValidUrl(req.url)) {
+      next();
+      return;
+    }
+    res.writeHead(400);
+    res.write("Not a proxy");
+    res.end();
+  });
+
   // Strip off the path prefix, if it exists.
   app.use(function (request, response, next) {
     var pathPrefix = __meteor_runtime_config__.ROOT_URL_PATH_PREFIX;