diff --git a/testing/marionette/client/marionette/marionette.py b/testing/marionette/client/marionette/marionette.py
index 2c2923261711..1235e3e9acdd 100644
--- a/testing/marionette/client/marionette/marionette.py
+++ b/testing/marionette/client/marionette/marionette.py
@@ -322,7 +322,7 @@ class Marionette(object):
 
         return unwrapped
 
-    def execute_js_script(self, script, script_args=None, timeout=True, new_sandbox=True):
+    def execute_js_script(self, script, script_args=None, timeout=True, new_sandbox=True, special_powers=False):
         if script_args is None:
             script_args = []
         args = self.wrapArguments(script_args)
@@ -331,10 +331,11 @@ class Marionette(object):
                                       value=script,
                                       args=args,
                                       timeout=timeout,
-                                      newSandbox=new_sandbox)
+                                      newSandbox=new_sandbox,
+                                      specialPowers=special_powers)
         return self.unwrapValue(response)
 
-    def execute_script(self, script, script_args=None, new_sandbox=True):
+    def execute_script(self, script, script_args=None, new_sandbox=True, special_powers=False):
         if script_args is None:
             script_args = []
         args = self.wrapArguments(script_args)
@@ -342,10 +343,11 @@ class Marionette(object):
                                      'value',
                                       value=script,
                                       args=args,
-                                      newSandbox=new_sandbox)
+                                      newSandbox=new_sandbox,
+                                      specialPowers=special_powers)
         return self.unwrapValue(response)
 
-    def execute_async_script(self, script, script_args=None, new_sandbox=True):
+    def execute_async_script(self, script, script_args=None, new_sandbox=True, special_powers=False):
         if script_args is None:
             script_args = []
         args = self.wrapArguments(script_args)
@@ -353,7 +355,8 @@ class Marionette(object):
                                       'value',
                                       value=script,
                                       args=args,
-                                      newSandbox=new_sandbox)
+                                      newSandbox=new_sandbox,
+                                      specialPowers=special_powers)
         return self.unwrapValue(response)
 
     def find_element(self, method, target, id=None):
diff --git a/testing/marionette/client/marionette/marionette_test.py b/testing/marionette/client/marionette/marionette_test.py
index e445ba91a83e..619f8c7d2b40 100644
--- a/testing/marionette/client/marionette/marionette_test.py
+++ b/testing/marionette/client/marionette/marionette_test.py
@@ -173,7 +173,7 @@ class MarionetteJSTestCase(CommonTestCase):
             args.append({'__marionetteArgs': {'appframe': frame}})
 
         try:
-            results = self.marionette.execute_js_script(js, args)
+            results = self.marionette.execute_js_script(js, args, special_powers=True)
 
             if launch_app:
                 self.kill_gaia_app(launch_app)
diff --git a/testing/marionette/client/marionette/tests/unit/test_specialpowers.py b/testing/marionette/client/marionette/tests/unit/test_specialpowers.py
index 5c3a491dc6d4..aea11a878f04 100644
--- a/testing/marionette/client/marionette/tests/unit/test_specialpowers.py
+++ b/testing/marionette/client/marionette/tests/unit/test_specialpowers.py
@@ -14,8 +14,8 @@ class TestSpecialPowersContent(MarionetteTestCase):
         result = self.marionette.execute_script("""
         SpecialPowers.setCharPref("%(pref)s", "%(value)s");
         return SpecialPowers.getCharPref("%(pref)s")
-        """ % {'pref': self.testpref, 'value': self.testvalue});
-        self.assertEqual(result, self.testvalue)
+        """ % {'pref': self.testpref, 'value': self.testvalue}, special_powers=True);
+        self.assertEqual(result, self.testvalue) 
 
     def test_prefs_after_navigate(self):
         test_html = self.marionette.absolute_url("test.html")
diff --git a/testing/marionette/client/marionette/tests/unit/unit-tests.ini b/testing/marionette/client/marionette/tests/unit/unit-tests.ini
index c6590ff6b48a..de2de526b1c9 100644
--- a/testing/marionette/client/marionette/tests/unit/unit-tests.ini
+++ b/testing/marionette/client/marionette/tests/unit/unit-tests.ini
@@ -13,6 +13,7 @@ b2g = false
 [test_perf.py]
 [test_log.py]
 [test_emulator.py]
+browser = false
 [test_execute_async_script.py]
 [test_execute_script.py]
 [test_simpletest_fail.js]
diff --git a/testing/marionette/marionette-actors.js b/testing/marionette/marionette-actors.js
index 275faedccda9..891bf49847a6 100644
--- a/testing/marionette/marionette-actors.js
+++ b/testing/marionette/marionette-actors.js
@@ -277,7 +277,6 @@ MarionetteDriverActor.prototype = {
       //add this to seenItems so we can guarantee the user will get winId as this window's id
       this.curBrowser.elementManager.seenItems[winId] = win;
     }
-    this.browsers[winId] = browser;
   },
 
   /**
@@ -438,7 +437,7 @@ MarionetteDriverActor.prototype = {
    * @return Sandbox
    *        Returns the sandbox
    */
-  createExecuteSandbox: function MDA_createExecuteSandbox(aWindow, marionette, args) {
+  createExecuteSandbox: function MDA_createExecuteSandbox(aWindow, marionette, args, specialPowers) {
     try {
       args = this.curBrowser.elementManager.convertWrappedArguments(args, aWindow);
     }
@@ -457,12 +456,14 @@ MarionetteDriverActor.prototype = {
       _chromeSandbox[fn] = marionette[fn].bind(marionette);
     });
 
-    loader.loadSubScript("chrome://specialpowers/content/specialpowersAPI.js",
-                         _chromeSandbox);
-    loader.loadSubScript("chrome://specialpowers/content/SpecialPowersObserverAPI.js",
-                         _chromeSandbox);
-    loader.loadSubScript("chrome://specialpowers/content/ChromePowers.js",
-                         _chromeSandbox);
+    if (specialPowers == true) {
+      loader.loadSubScript("chrome://specialpowers/content/specialpowersAPI.js",
+                           _chromeSandbox);
+      loader.loadSubScript("chrome://specialpowers/content/SpecialPowersObserverAPI.js",
+                           _chromeSandbox);
+      loader.loadSubScript("chrome://specialpowers/content/ChromePowers.js",
+                           _chromeSandbox);
+    }
 
     return _chromeSandbox;
   },
@@ -541,7 +542,7 @@ MarionetteDriverActor.prototype = {
 
     let curWindow = this.getCurrentWindow();
     let marionette = new Marionette(this, curWindow, "chrome", this.marionetteLog, this.marionettePerf);
-    let _chromeSandbox = this.createExecuteSandbox(curWindow, marionette, aRequest.args);
+    let _chromeSandbox = this.createExecuteSandbox(curWindow, marionette, aRequest.args, aRequest.specialPowers);
     if (!_chromeSandbox)
       return;
 
@@ -688,7 +689,7 @@ MarionetteDriverActor.prototype = {
       chromeAsyncReturnFunc(marionette.generate_results(), 0);
     }
 
-    let _chromeSandbox = this.createExecuteSandbox(curWindow, marionette, aRequest.args);
+    let _chromeSandbox = this.createExecuteSandbox(curWindow, marionette, aRequest.args, aRequest.specialPowers);
     if (!_chromeSandbox)
       return;
 
@@ -822,9 +823,11 @@ MarionetteDriverActor.prototype = {
           //enable Marionette in that browser window
           this.startBrowser(foundWin, false);
         }
-        utils.window = foundWin;
+        else {
+          utils.window = foundWin;
+          this.curBrowser = this.browsers[winId];
+        }
         foundWin.focus();
-        this.curBrowser = this.browsers[winId];
         this.sendOk();
         return;
       }