diff --git a/test/asset/test-ui.js b/test/asset/test-ui.js
index c4f038b5d..5456fd2ee 100644
--- a/test/asset/test-ui.js
+++ b/test/asset/test-ui.js
@@ -128,6 +128,15 @@
     init();
   });
 
+  // used to indicate testing a foreign file
+  ui.isForeign = RegExp('^(\\w+:)?//').test(build);
+
+  // used to indicate testing a modularized build
+  ui.isModularize = /\b(?:commonjs|(index|main)\.js|lodash-(?:amd|node)|modularize|npm)\b/.test([location.pathname, location.search]);
+
+  // used to indicate testing in Sauce Labs' automated test cloud
+  ui.isSauceLabs = location.port == '9001';
+
   // expose Lo-Dash build file path
   ui.buildPath = (function() {
     var result;
@@ -170,12 +179,6 @@
     'loadEventEnd': 0
   };
 
-  // used to indicate testing a modularized build
-  ui.isModularize = /\b(?:commonjs|(index|main)\.js|lodash-(?:amd|node)|modularize|npm)\b/.test([location.pathname, location.search, ui.buildPath]);
-
-  // used to indicate testing in Sauce Labs' automated test cloud
-  ui.isSauceLabs = location.port == '9001';
-
   // expose `ui`
   window.ui = ui;
 
diff --git a/test/asset/worker.js b/test/asset/worker.js
index 75f21c9a5..d925de523 100644
--- a/test/asset/worker.js
+++ b/test/asset/worker.js
@@ -1,6 +1,10 @@
 addEventListener('message', function(e) {
   if (e.data) {
-    importScripts('../' + e.data);
+    try {
+      importScripts('../' + e.data);
+    } catch(e) {
+      self._ = {};
+    }
     postMessage(_.VERSION);
   }
 }, false);
diff --git a/test/index.html b/test/index.html
index 9606cf2a8..96a59fc92 100644
--- a/test/index.html
+++ b/test/index.html
@@ -168,7 +168,7 @@
 				removeBizarroMethods();
 			}
 			// load test scripts
-			document.write(ui.urlParams.loader == 'none'
+			document.write((ui.isForeign || ui.urlParams.loader == 'none')
 				? '<script src="' + ui.buildPath + '"><\/script><script src="test.js"><\/script>'
 				: '<script data-dojo-config="async:1" src="' + ui.loaderPath + '"><\/script>'
 			);
@@ -182,7 +182,7 @@
 				if (window.curl) {
 					curl.config({ 'apiName': 'require' });
 				}
-				if (!window.require) {
+				if (ui.isForeign || !window.require) {
 					return;
 				}
 				// avoid reporting tests to Sauce Labs when script load errors occur
@@ -256,8 +256,6 @@
 
 				function loadModulesAndTests() {
 					require(getConfig(), ['lodash', 'shimmed', 'underscore'], function(lodash, shimmed, underscore) {
-						var oldDash = window._;
-
 						if (shimmed && shimmed.noConflict) {
 							shimmedModule = shimmed.noConflict();
 							shimmedModule.moduleName = 'shimmed';
@@ -270,7 +268,7 @@
 							lodashModule = lodash;
 							lodashModule.moduleName = 'lodash';
 						}
-						if (oldDash || ui.isModularize) {
+						if (ui.isModularize) {
 							window._ = lodash;
 						}
 						if (ui.isModularize) {
diff --git a/test/test.js b/test/test.js
index 3171a1bfe..e4c5f6e1b 100644
--- a/test/test.js
+++ b/test/test.js
@@ -23,6 +23,7 @@
       body = root.document && root.document.body,
       create = Object.create,
       freeze = Object.freeze,
+      JSON = root.JSON,
       noop = function() {},
       params = root.arguments,
       push = Array.prototype.push,
@@ -30,9 +31,6 @@
       system = root.system,
       toString = Object.prototype.toString;
 
-  var JSON = root.JSON,
-      Worker = document && root.Worker;
-
   /** The file path of the Lo-Dash file to test */
   var filePath = (function() {
     var min = 0,
@@ -68,6 +66,7 @@
   var ui = root.ui || (root.ui = {
     'buildPath': filePath,
     'loaderPath': '',
+    'isModularize': /\b(?:commonjs|(index|main)\.js|lodash-(?:amd|node)|modularize|npm)\b/.test(filePath),
     'urlParams': {}
   });
 
@@ -78,7 +77,7 @@
   var isJava = !document && !!root.java;
 
   /** Used to indicate testing a modularized build */
-  var isModularize = ui.isModularize || /\b(?:commonjs|(index|main)\.js|lodash-(?:amd|node)|modularize|npm)\b/.test([ui.buildPath, ui.urlParams.build, basename]);
+  var isModularize = ui.isModularize;
 
   /** Detect if testing `npm` modules */
   var isNpm = isModularize && /\bnpm\b/.test([ui.buildPath, ui.urlParams.build]);
@@ -89,6 +88,9 @@
   /** Detect if running in Rhino */
   var isRhino = isJava && typeof global == 'function' && global().Array === root.Array;
 
+  /** Detect support for testing Web Workers */
+  var Worker = !(ui.isForeign || isModularize) && document && root.Worker;
+
   /** Use a single "load" function */
   var load = (typeof require == 'function' && !amd)
     ? require
@@ -403,7 +405,7 @@
 
   // add web worker
   (function() {
-    if (!Worker || isModularize) {
+    if (!Worker) {
       return;
     }
     var worker = new Worker('./asset/worker.js?t=' + (+new Date));
@@ -439,7 +441,7 @@
     });
 
     test('supports loading ' + basename + ' as the "underscore" module', 1, function() {
-      if (amd && !/dojo/.test(ui.loaderPath)) {
+      if (amd) {
         strictEqual((underscoreModule || {}).moduleName, 'underscore');
       }
       else {
@@ -448,7 +450,7 @@
     });
 
     asyncTest('supports loading ' + basename + ' in a web worker', 1, function() {
-      if (Worker && !isModularize) {
+      if (Worker) {
         var limit = 15000,
             start = +new Date;