diff --git a/layout/tools/reftest/runreftestb2g.py b/layout/tools/reftest/runreftestb2g.py
index afffe4e18fe..d11c6e01ec3 100644
--- a/layout/tools/reftest/runreftestb2g.py
+++ b/layout/tools/reftest/runreftestb2g.py
@@ -100,6 +100,11 @@ class B2GOptions(ReftestOptions):
                     type = "string", dest = "pidFile",
                     help = "name of the pidfile to generate")
         defaults["pidFile"] = ""
+        self.add_option("--gecko-path", action="store",
+                        type="string", dest="geckoPath",
+                        help="the path to a gecko distribution that should "
+                        "be installed on the emulator prior to test")
+        defaults["geckoPath"] = None
         defaults["remoteTestRoot"] = None
         defaults["logFile"] = "reftest.log"
         defaults["autorun"] = True
@@ -125,6 +130,9 @@ class B2GOptions(ReftestOptions):
 
         options.webServer = options.remoteWebServer
 
+        if options.geckoPath and not options.emulator:
+            self.error("You must specify --emulator if you specify --gecko-path")
+
         #if not options.emulator and not options.deviceIP:
         #    print "ERROR: you must provide a device IP"
         #    return None
@@ -447,6 +455,8 @@ def main(args=sys.argv[1:]):
         host,port = options.marionette.split(':')
         kwargs['host'] = host
         kwargs['port'] = int(port)
+    if options.geckoPath:
+        kwargs['gecko_path'] = options.geckoPath
     marionette = Marionette(**kwargs)
     auto.marionette = marionette