DynamicsWorld - forward declaration

Hi all !

I've builded Bullet 2.77 and ogreBullet to add physics simulation to my game engine.

Here is my headers for bullet and ogrebullet :

#include "OGREBULLET/Collisions/OgreBulletCollisions.h"
#include "OGREBULLET/Dynamics/OgreBulletDynamics.h"

Here is the lib linked to the program :

libs/libOgreBulletCol.a
libs/libOgreBulletDyn.a

libs/libBulletDynamics.a
libs/libBulletCollision.a
libs/libLinearMath.a

With no code relative to bullet within the project, the project compile fine and run with no problems.
But when i add this line :

OgreBulletDynamics::DynamicsWorld * mWorld = new OgreBulletDynamics::DynamicsWorld(this->Scene,Ogre::AxisAlignedBox(Ogre::Vector3(-10000,-10000,-10000),Ogre::Vector3(10000,10000,10000)),Ogre::Vector3(0,-9.81,0));

I got an error during building :

In file included from src/Main.cc:20:
src/StateMenu.cc: In member function ‘virtual void StateMenu::init()’:
src/StateMenu.cc:36: error: invalid use of incomplete type ‘struct OgreBulletDynamics::DynamicsWorld’
include/OGREBULLET/Dynamics/OgreBulletDynamicsPreRequisites.h:45: error: forward declaration of ‘struct OgreBulletDynamics::DynamicsWorld’
make: *** [Bli] Erreur 1



Is someone has an idea ?

Greetings,

Gouwi