diff --git a/compiler/optimizing/select_generator.h b/compiler/optimizing/select_generator.h
index 4f13917..7aa0803 100644
--- a/compiler/optimizing/select_generator.h
+++ b/compiler/optimizing/select_generator.h
@@ -57,11 +57,12 @@
 #ifndef ART_COMPILER_OPTIMIZING_SELECT_GENERATOR_H_
 #define ART_COMPILER_OPTIMIZING_SELECT_GENERATOR_H_
 
+#include "base/macros.h"
 #include "base/scoped_arena_containers.h"
 #include "optimization.h"
 #include "optimizing/nodes.h"
 
-namespace art {
+namespace art HIDDEN {
 
 class HSelectGenerator : public HOptimization {
  public: