diff --git a/src/tint/castable_test.cc b/src/tint/castable_test.cc
index 0e01172..e5698f9 100644
--- a/src/tint/castable_test.cc
+++ b/src/tint/castable_test.cc
@@ -20,7 +20,6 @@
 #include "gtest/gtest.h"
 
 namespace tint {
-namespace {
 
 struct Animal : public tint::Castable<Animal> {};
 struct Amphibian : public tint::Castable<Amphibian, Animal> {};
@@ -32,6 +31,8 @@
 struct Gecko : public tint::Castable<Gecko, Lizard> {};
 struct Iguana : public tint::Castable<Iguana, Lizard> {};
 
+namespace {
+
 TEST(CastableBase, Is) {
   std::unique_ptr<CastableBase> frog = std::make_unique<Frog>();
   std::unique_ptr<CastableBase> bear = std::make_unique<Bear>();