diff --git a/packages/webapp/css_detect.css b/packages/webapp/css_detect.css
deleted file mode 100644
index fa54606703..0000000000
--- a/packages/webapp/css_detect.css
+++ /dev/null
@@ -1,3 +0,0 @@
-._meteor_detect_css {
-    width: 0px;
-}
\ No newline at end of file
diff --git a/packages/webapp/package.js b/packages/webapp/package.js
index a8f9d66e66..fab6a96434 100644
--- a/packages/webapp/package.js
+++ b/packages/webapp/package.js
@@ -22,5 +22,4 @@ Package.on_use(function (api) {
   api.export(['WebApp'], 'client');
   api.add_files('webapp_server.js', 'server');
   api.add_files('webapp_client.js', 'client');
-  api.add_files('css_detect.css', 'client');
 });
diff --git a/packages/webapp/webapp_client.js b/packages/webapp/webapp_client.js
index 09a0eb44e2..2a8a577532 100644
--- a/packages/webapp/webapp_client.js
+++ b/packages/webapp/webapp_client.js
@@ -3,9 +3,9 @@ WebApp = {
   _isCssLoaded: function () {
     return _.find(document.styleSheets, function (sheet) {
       if (sheet.cssText && !sheet.cssRules) // IE8
-        return sheet.cssText.match(/_meteor_detect_css/);
-      return _.find(sheet.cssRules, function (rule) {
-        return rule.selectorText === '._meteor_detect_css';
+        return !sheet.cssText.match(/meteor-css-not-found-error/);
+      return !_.find(sheet.cssRules, function (rule) {
+        return rule.selectorText === '.meteor-css-not-found-error';
       });
     });
   }
diff --git a/packages/webapp/webapp_server.js b/packages/webapp/webapp_server.js
index e5ee0053a6..1e60ddeb63 100644
--- a/packages/webapp/webapp_server.js
+++ b/packages/webapp/webapp_server.js
@@ -397,7 +397,6 @@ var runWebAppServer = function () {
     // in `about:config` (it is on by default in FF 24).
     if (info.sourceMapUrl)
       res.setHeader('X-SourceMap', info.sourceMapUrl);
-
     send(req, path.join(clientDir, info.path))
       .maxage(maxAge)
       .hidden(true)  // if we specified a dotfile in the manifest, serve it
@@ -445,8 +444,17 @@ var runWebAppServer = function () {
 
     var request = WebApp.categorizeRequest(req);
 
+    if (request.url.query && request.url.query['meteor_css_resource']) {
+      // In this case, we're requesting a CSS resource in the meteor-specific
+      // way, but we don't have it.  Serve a static css file that indicates that
+      // we didn't have it, so we can detect that and refresh.
+      headers['Content-Type'] = 'text/css; charset=utf-8';
+      res.writeHead(200, headers);
+      res.write(".meteor-css-not-found-error { width: 0px;}");
+      res.end();
+      return undefined;
+    }
     res.writeHead(200, headers);
-
     var requestSpecificHtml = htmlAttributes(boilerplateHtml, request);
     res.write(requestSpecificHtml);
     res.end();
diff --git a/tools/bundler.js b/tools/bundler.js
index 9d93ddd75f..b0c3f1c841 100644
--- a/tools/bundler.js
+++ b/tools/bundler.js
@@ -313,15 +313,18 @@ _.extend(File.prototype, {
     return self.contents().length;
   },
 
-  // Set the URL of this file to "/<hash><suffix>". suffix will
-  // typically be used to pick a reasonable extension. Also set
-  // cacheable to true, since the file's name is now derived from its
-  // contents.
-  setUrlToHash: function (suffix) {
+  // Set the URL (and target path) of this file to "/<hash><suffix>". suffix
+  // will typically be used to pick a reasonable extension. Also set cacheable
+  // to true, since the file's name is now derived from its contents.
+
+  // Also allow a special second suffix that will *only* be postpended to the
+  // url, useful for query parameters.
+  setUrlToHash: function (fileAndUrlSuffix, urlSuffix) {
     var self = this;
-    self.url = "/" + self.hash() + suffix;
+    urlSuffix = urlSuffix || "";
+    self.url = "/" + self.hash() + fileAndUrlSuffix + urlSuffix;
     self.cacheable = true;
-    self.targetPath = self.hash() + suffix;
+    self.targetPath = self.hash() + fileAndUrlSuffix;
   },
 
   // Append "?<hash>" to the URL and mark the file as cacheable.
@@ -766,7 +769,7 @@ _.extend(ClientTarget.prototype, {
     allCss = minifiers.CleanCSSProcess(allCss);
 
     self.css = [new File({ data: new Buffer(allCss, 'utf8') })];
-    self.css[0].setUrlToHash(".css");
+    self.css[0].setUrlToHash(".css", "?meteor_css_resource=true");
   },
 
   // XXX Instead of packaging the boilerplate in the client program, the