--- a/testing/mozharness/configs/android/androidarm.py
+++ b/testing/mozharness/configs/android/androidarm.py
@@ -188,16 +188,17 @@ config = {
                 "--suite=jstestbrowser",
             ],
             "tests": ["../jsreftest/tests/jstests.list"],
         },
         "xpcshell": {
             "run_filename": "remotexpcshelltests.py",
             "testsdir": "xpcshell",
             "options": [
+                "--dm_trans=sut",
                 "--deviceIP=%(device_ip)s",
                 "--devicePort=%(device_port)s",
                 "--xre-path=%(xre_path)s",
                 "--testing-modules-dir=%(modules_dir)s",
                 "--apk=%(installer_path)s",
                 "--no-logfiles",
                 "--symbols-path=%(symbols_path)s",
                 "--manifest=tests/xpcshell.ini",

--- a/testing/mozharness/configs/android/androidx86.py
+++ b/testing/mozharness/configs/android/androidx86.py
@@ -114,17 +114,18 @@ config = {
                         "--http-port=%(http_port)s",
                         "--ssl-port=%(ssl_port)s",
                         "--httpd-path", "%(modules_dir)s",
                         "--symbols-path=%(symbols_path)s",
                     ],
         },
         "xpcshell": {
             "run_filename": "remotexpcshelltests.py",
-            "options": ["--deviceIP=%(device_ip)s",
+            "options": ["--dm_trans=sut",
+                        "--deviceIP=%(device_ip)s",
                         "--devicePort=%(device_port)s",
                         "--xre-path=%(xre_path)s",
                         "--testing-modules-dir=%(modules_dir)s",
                         "--apk=%(installer_path)s",
                         "--no-logfiles",
                         "--symbols-path=%(symbols_path)s",
                         "--manifest=tests/xpcshell.ini",
                         "--log-raw=%(raw_log_file)s",

--- a/testing/xpcshell/xpcshellcommandline.py
+++ b/testing/xpcshell/xpcshellcommandline.py
@@ -108,18 +108,18 @@ def add_common_arguments(parser):
 def add_remote_arguments(parser):
     parser.add_argument("--deviceIP", action="store", type=str, dest="deviceIP",
                         help="ip address of remote device to test")
 
     parser.add_argument("--devicePort", action="store", type=str, dest="devicePort",
                         default=20701, help="port of remote device to test")
 
     parser.add_argument("--dm_trans", action="store", type=str, dest="dm_trans",
-                        choices=["adb", "sut"], default="sut",
-                        help="the transport to use to communicate with device: [adb|sut]; default=sut")
+                        choices=["adb", "sut"], default="adb",
+                        help="the transport to use to communicate with device: [adb|sut]; default=adb")
 
     parser.add_argument("--objdir", action="store", type=str, dest="objdir",
                         help="local objdir, containing xpcshell binaries")
 
 
     parser.add_argument("--apk", action="store", type=str, dest="localAPK",
                         help="local path to Fennec APK")