diff --git a/devtoolslib/android_shell.py b/devtoolslib/android_shell.py
index c3bed33..a4a7d16 100644
--- a/devtoolslib/android_shell.py
+++ b/devtoolslib/android_shell.py
@@ -199,7 +199,7 @@
     return len(subprocess.check_output(self._adb_command([
         'shell', 'pm', 'list', 'packages', _MOJO_SHELL_PACKAGE_NAME]))) > 0
 
-  def check_device(self):
+  def check_device(self, require_root=False):
     """Verifies if the device configuration allows adb to run.
 
     If a target device was indicated in the constructor, it checks that the
@@ -234,6 +234,9 @@
     if not device_list[0].endswith('device'):
       return False, 'Connected device is not available.'
 
+    if require_root and not self._run_adb_as_root():
+      return False, 'Cannot run on an unrooted device.'
+
     return True, None
 
   def install_apk(self, shell_apk_path):
diff --git a/devtoolslib/shell_arguments.py b/devtoolslib/shell_arguments.py
index 20f512e..f479248 100644
--- a/devtoolslib/shell_arguments.py
+++ b/devtoolslib/shell_arguments.py
@@ -190,7 +190,8 @@
                          logcat_tags=shell_config.logcat_tags,
                          verbose_pipe=verbose_pipe)
 
-    device_status, error = shell.check_device()
+    device_status, error = shell.check_device(
+        require_root=shell_config.require_root)
     if not device_status:
       raise ShellConfigurationException('Device check failed: ' + error)
     if shell_config.shell_path:
diff --git a/devtoolslib/shell_config.py b/devtoolslib/shell_config.py
index 20d2e23..227b979 100644
--- a/devtoolslib/shell_config.py
+++ b/devtoolslib/shell_config.py
@@ -36,6 +36,7 @@
     self.adb_path = None
     self.target_device = None
     self.logcat_tags = None
+    self.require_root = False
 
     # Desktop-only.
     self.use_osmesa = None
diff --git a/mojo_test b/mojo_test
index 2cf84b9..45cdb0d 100755
--- a/mojo_test
+++ b/mojo_test
@@ -62,6 +62,9 @@
 
   try:
     config = shell_config.get_shell_config(script_args)
+    if script_args.android:
+      # We need root to have the stdout of the shell available on the host.
+      config.require_root = True
     shell, common_shell_args = shell_arguments.get_shell(config, shell_args)
   except shell_config.ShellConfigurationException as e:
     print e