diff --git a/aos/starter/mock_starter.cc b/aos/starter/mock_starter.cc
index 9f9a2b5..541e17f 100644
--- a/aos/starter/mock_starter.cc
+++ b/aos/starter/mock_starter.cc
@@ -1,7 +1,6 @@
 #include "aos/starter/mock_starter.h"
 
-namespace aos {
-namespace starter {
+namespace aos::starter {
 
 MockStarter::MockStarter(aos::EventLoop *event_loop)
     : event_loop_(event_loop),
@@ -119,5 +118,4 @@
   }
 }
 
-}  // namespace starter
-}  // namespace aos
+}  // namespace aos::starter