diff --git a/python-packages/adb/device.py b/python-packages/adb/device.py
index 8694ab4b3..392fafea8 100644
--- a/python-packages/adb/device.py
+++ b/python-packages/adb/device.py
@@ -198,7 +198,7 @@ class AndroidDevice(object):
     _RETURN_CODE_SEARCH_LENGTH = len('{0}255\r\n'.format(_RETURN_CODE_DELIMITER))
 
     # Feature name strings.
-    SHELL_PROTOCOL_FEATURE = 'shell_2'
+    SHELL_PROTOCOL_FEATURE = 'shell_v2'
 
     def __init__(self, serial, product=None):
         self.serial = serial
diff --git a/python-packages/adb/test_device.py b/python-packages/adb/test_device.py
index bef748831..a1e659fd9 100644
--- a/python-packages/adb/test_device.py
+++ b/python-packages/adb/test_device.py
@@ -215,12 +215,24 @@ class ShellTest(DeviceTest):
         if self.device.SHELL_PROTOCOL_FEATURE not in self.device.features:
             raise unittest.SkipTest('shell protocol unsupported on this device')
 
+        # Shell protocol should be used by default.
         result = self.device.shell_nocheck(
                 shlex.split('echo foo; echo bar >&2; exit 17'))
         self.assertEqual(17, result[0])
         self.assertEqual('foo' + self.device.linesep, result[1])
         self.assertEqual('bar' + self.device.linesep, result[2])
 
+        self.assertEqual(17, self._interactive_shell([], 'exit 17'))
+
+        # -x flag should disable shell protocol.
+        result = self.device.shell_nocheck(
+                shlex.split('-x echo foo; echo bar >&2; exit 17'))
+        self.assertEqual(0, result[0])
+        self.assertEqual('foo{0}bar{0}'.format(self.device.linesep), result[1])
+        self.assertEqual('', result[2])
+
+        self.assertEqual(0, self._interactive_shell(['-x'], 'exit 17'))
+
     def test_non_interactive_sigint(self):
         """Tests that SIGINT in a non-interactive shell kills the process.