diff --git a/compiler/optimizing/code_generator_utils.h b/compiler/optimizing/code_generator_utils.h
index 64665ad..9d9ab2b 100644
--- a/compiler/optimizing/code_generator_utils.h
+++ b/compiler/optimizing/code_generator_utils.h
@@ -21,7 +21,9 @@
 #include <cstdlib>
 #include <limits>
 
-namespace art {
+#include "base/macros.h"
+
+namespace art HIDDEN {
 
 class HInstruction;