diff --git a/compiler/optimizing/loop_optimization_test.cc b/compiler/optimizing/loop_optimization_test.cc
index bda2528..71c6988 100644
--- a/compiler/optimizing/loop_optimization_test.cc
+++ b/compiler/optimizing/loop_optimization_test.cc
@@ -14,12 +14,13 @@
  * limitations under the License.
  */
 
+#include "base/macros.h"
 #include "code_generator.h"
 #include "driver/compiler_options.h"
 #include "loop_optimization.h"
 #include "optimizing_unit_test.h"
 
-namespace art {
+namespace art HIDDEN {
 
 /**
  * Fixture class for the loop optimization tests. These unit tests focus