diff --git a/source/RobotAPI/interface/objectpose/object_pose_types.ice b/source/RobotAPI/interface/objectpose/object_pose_types.ice
index 097c6890165ed7c943630cc845b5bceb73c1294c..19aa0e2df527ac84bed7a392e0c50818696189a1 100644
--- a/source/RobotAPI/interface/objectpose/object_pose_types.ice
+++ b/source/RobotAPI/interface/objectpose/object_pose_types.ice
@@ -48,13 +48,17 @@ module armarx
         sequence<ObjectID> ObjectIDSeq;
 
 
-        struct AABB
+        class AABB
         {
             Vector3Base center;
             Vector3Base extents;
         };
 
-        struct Box
+        /**
+         * @brief A 3D box.
+         * Box is a a class to allow it being null.
+         */
+        class Box
         {
             Vector3Base position;
             QuaternionBase orientation;
@@ -84,7 +88,7 @@ module armarx
                 /// Source timestamp.
                 long timestampMicroSeconds = -1;
 
-                /// Object bounding box in object's local coordinate frame.
+                /// Object bounding box in object's local coordinate frame. May be null.
                 Box localOOBB;
             };
             sequence<ProvidedObjectPose> ProvidedObjectPoseSeq;
@@ -114,7 +118,7 @@ module armarx
                 /// Source timestamp.
                 long timestampMicroSeconds = -1;
 
-                /// Object bounding box in object's local coordinate frame.
+                /// Object bounding box in object's local coordinate frame. May be null.
                 Box localOOBB;
             };
             sequence<ObjectPose> ObjectPoseSeq;