diff --git a/mobly/controllers/android_device.py b/mobly/controllers/android_device.py
index cd0d6a9..cb9ab52 100644
--- a/mobly/controllers/android_device.py
+++ b/mobly/controllers/android_device.py
@@ -457,7 +457,7 @@
         self._is_rebooting = False
         self.adb = adb.AdbProxy(serial)
         self.fastboot = fastboot.FastbootProxy(serial)
-        if not self.is_bootloader and self.is_rootable:
+        if self.is_rootable:
             self.root_adb()
         self.services = service_manager.ServiceManager(self)
         self.services.register(SERVICE_NAME_LOGCAT,
@@ -788,7 +788,7 @@
 
     @property
     def is_rootable(self):
-        return self.build_info['debuggable'] == '1'
+        return not self.is_bootloader and self.build_info['debuggable'] == '1'
 
     @property
     def model(self):
@@ -834,6 +834,8 @@
         mode per security restrictions.
         """
         self.adb.root()
+        # `root` causes the device to temporarily disappear from adb.
+        # So we need to wait for the device to come back before proceeding.
         self.adb.wait_for_device(
             timeout=DEFAULT_TIMEOUT_BOOT_COMPLETION_SECOND)