diff --git a/Demos/ConcaveDemo/ConcavePhysicsDemo.cpp b/Demos/ConcaveDemo/ConcavePhysicsDemo.cpp
index 296af478b..d4f40df41 100644
--- a/Demos/ConcaveDemo/ConcavePhysicsDemo.cpp
+++ b/Demos/ConcaveDemo/ConcavePhysicsDemo.cpp
@@ -20,10 +20,12 @@ subject to the following restrictions:
 #include "GL_ShapeDrawer.h"
 #include "GlutStuff.h"
 
-#include "btBulletWorldImporter.h"
-
 #define SERIALIZE_TO_DISK 1
 
+#ifndef SERIALIZE_TO_DISK
+#include "btBulletWorldImporter.h"
+#endif //SERIALIZE_TO_DISK
+
 //by default, the sample only (de)serializes the BVH to disk. 
 //If you enable the SERIALIZE_SHAPE define then it will serialize the entire collision shape
 //then the animation will not play, because it is using the deserialized vertices