diff --git a/compiler/driver/compiler_options_map.h b/compiler/driver/compiler_options_map.h
index 7e2f846..b2dd57d 100644
--- a/compiler/driver/compiler_options_map.h
+++ b/compiler/driver/compiler_options_map.h
@@ -21,10 +21,11 @@
 #include <vector>
 
 #include "base/compiler_filter.h"
+#include "base/macros.h"
 #include "base/variant_map.h"
 #include "cmdline_types.h"
 
-namespace art {
+namespace art HIDDEN {
 
 enum class ProfileMethodsCheck : uint8_t;