diff --git a/aos/testing/random_seed.h b/aos/testing/random_seed.h
index 825e7b1..11bfe99 100644
--- a/aos/testing/random_seed.h
+++ b/aos/testing/random_seed.h
@@ -1,15 +1,13 @@
 #ifndef AOS_TESTING_RANDOM_SEED_H_
 #define AOS_TESTING_RANDOM_SEED_H_
 
-namespace aos {
-namespace testing {
+namespace aos::testing {
 
 // Returns the random seed to use for testing.
 //
 // This is ${TEST_RANDOM_SEED} if it is set or 1.
 int RandomSeed();
 
-}  // namespace testing
-}  // namespace aos
+}  // namespace aos::testing
 
 #endif  // AOS_TESTING_RANDOM_SEED_H_