diff --git a/mobly/controllers/android_device_lib/service_manager.py b/mobly/controllers/android_device_lib/service_manager.py
index 710e133..78cc170 100644
--- a/mobly/controllers/android_device_lib/service_manager.py
+++ b/mobly/controllers/android_device_lib/service_manager.py
@@ -235,7 +235,6 @@
         """Resumes the specified services.
 
         Services will be resumed in the order specified by the input list.
-        No-op for services that are already running.
 
         Args:
             service_alises: list of strings, the names of services to start.
@@ -247,8 +246,7 @@
                     'No service is registered under the name "%s", cannot resume.'
                     % name)
             service = self._service_objects[name]
-            if not service.is_alive:
-                service.resume()
+            service.resume()
 
     def __getattr__(self, name):
         """Syntactic sugar to enable direct access of service objects by alias.