diff --git a/include/J3ML/Geometry.h b/include/J3ML/Geometry.h
index 839162d..24f53ad 100644
--- a/include/J3ML/Geometry.h
+++ b/include/J3ML/Geometry.h
@@ -14,6 +14,10 @@ namespace Geometry {
     };
 
     class Rectangle;
+    class AABB;
+    class OBB;
+    class Capsule;
+    class Frustum;
     class OBB2D;
     class Line2D;
     class Ray2D;