diff --git a/src/BulletMultiThreaded/SpuNarrowPhaseCollisionTask/Box.h b/src/BulletMultiThreaded/SpuNarrowPhaseCollisionTask/Box.h
index c5b68743c..9bc2ebf51 100644
--- a/src/BulletMultiThreaded/SpuNarrowPhaseCollisionTask/Box.h
+++ b/src/BulletMultiThreaded/SpuNarrowPhaseCollisionTask/Box.h
@@ -24,8 +24,13 @@ subject to the following restrictions:
 
 #include <math.h>
 
-//#include "BulletMultiThreaded/vectormath/scalar/cpp/vectormath_aos.h"
+///only use a system-wide vectormath_aos.h on CELLOS_LV2 or if USE_SYSTEM_VECTORMATH
+#if defined(__CELLOS_LV2__) || defined (USE_SYSTEM_VECTORMATH)
 #include <vectormath_aos.h>
+#else
+#include "BulletMultiThreaded/vectormath/scalar/cpp/vectormath_aos.h"
+#endif
+
 
 
 using namespace Vectormath::Aos;
diff --git a/src/BulletMultiThreaded/vectormath2bullet.h b/src/BulletMultiThreaded/vectormath2bullet.h
index efc7a3c92..5a4944a55 100644
--- a/src/BulletMultiThreaded/vectormath2bullet.h
+++ b/src/BulletMultiThreaded/vectormath2bullet.h
@@ -30,8 +30,13 @@
 #ifndef AOS_VECTORMATH_BULLET_CONVERT_H
 #define AOS_VECTORMATH_BULLET_CONVERT_H
 
+
+///only use a system-wide vectormath_aos.h on CELLOS_LV2 or if USE_SYSTEM_VECTORMATH
+#if defined(__CELLOS_LV2__) || defined (USE_SYSTEM_VECTORMATH)
 #include <vectormath_aos.h>
-//#include "BulletMultiThreaded/vectormath/scalar/cpp/vectormath_aos.h"
+#else
+#include "BulletMultiThreaded/vectormath/scalar/cpp/vectormath_aos.h"
+#endif
 
 #include "LinearMath/btVector3.h"
 #include "LinearMath/btQuaternion.h"