diff --git a/OVP/D3D9Client/Scene.cpp b/OVP/D3D9Client/Scene.cpp
index d874a950e..b8edb212f 100644
--- a/OVP/D3D9Client/Scene.cpp
+++ b/OVP/D3D9Client/Scene.cpp
@@ -3685,7 +3685,7 @@ void Scene::RenderGlares()
 
 // ===========================================================================================
 //
-bool Scene::IsVisibleInCamera(D3DXVECTOR3 *pCnt, float radius)
+bool Scene::IsVisibleInCamera(const D3DXVECTOR3 *pCnt, float radius)
 {
 	float z = Camera.z.x*pCnt->x + Camera.z.y*pCnt->y + Camera.z.z*pCnt->z;
 	if (z<(-radius)) return false;
diff --git a/OVP/D3D9Client/Scene.h b/OVP/D3D9Client/Scene.h
index c31b449a7..4635a487a 100644
--- a/OVP/D3D9Client/Scene.h
+++ b/OVP/D3D9Client/Scene.h
@@ -342,7 +342,7 @@ class Scene {
 	bool			CameraPan(VECTOR3 pan, double speed);
 
 					// Check if a sphere located in pCnt (relative to cam) with a specified radius is visible in a camera
-	bool			IsVisibleInCamera(D3DXVECTOR3 *pCnt, float radius);
+	bool			IsVisibleInCamera(const D3DXVECTOR3 *pCnt, float radius);
 	bool			IsProxyMesh();
 	bool            CameraDirection2Viewport(const VECTOR3 &dir, int &x, int &y);
 	double			GetTanAp() const { return tan(Camera.aperture); }