diff --git a/scene/3d/physics/collision_object_3d.cpp b/scene/3d/physics/collision_object_3d.cpp
index ae29565daf8..7d3da639d3b 100644
--- a/scene/3d/physics/collision_object_3d.cpp
+++ b/scene/3d/physics/collision_object_3d.cpp
@@ -713,6 +713,7 @@ CollisionObject3D::CollisionObject3D(RID p_rid, bool p_area) {
 	rid = p_rid;
 	area = p_area;
 	set_notify_transform(true);
+	_define_ancestry(AncestralClass::COLLISION_OBJECT_3D);
 
 	if (p_area) {
 		PhysicsServer3D::get_singleton()->area_attach_object_instance_id(rid, get_instance_id());
@@ -755,8 +756,6 @@ CollisionObject3D::CollisionObject3D() {
 }
 
 CollisionObject3D::~CollisionObject3D() {
-	_define_ancestry(AncestralClass::COLLISION_OBJECT_3D);
-
 	ERR_FAIL_NULL(PhysicsServer3D::get_singleton());
 	PhysicsServer3D::get_singleton()->free(rid);
 }
diff --git a/scene/3d/physics/physics_body_3d.cpp b/scene/3d/physics/physics_body_3d.cpp
index 49638328c1f..a958a95471d 100644
--- a/scene/3d/physics/physics_body_3d.cpp
+++ b/scene/3d/physics/physics_body_3d.cpp
@@ -53,6 +53,7 @@ void PhysicsBody3D::_bind_methods() {
 
 PhysicsBody3D::PhysicsBody3D(PhysicsServer3D::BodyMode p_mode) :
 		CollisionObject3D(PhysicsServer3D::get_singleton()->body_create(), false) {
+	_define_ancestry(AncestralClass::PHYSICS_BODY_3D);
 	set_body_mode(p_mode);
 }
 
@@ -220,10 +221,6 @@ PackedStringArray PhysicsBody3D::get_configuration_warnings() const {
 	return warnings;
 }
 
-PhysicsBody3D::PhysicsBody3D() {
-	_define_ancestry(AncestralClass::PHYSICS_BODY_3D);
-}
-
 ///////////////////////////////////////
 
 //so, if you pass 45 as limit, avoid numerical precision errors when angle is 45.
diff --git a/scene/3d/physics/physics_body_3d.h b/scene/3d/physics/physics_body_3d.h
index 5c5608010dd..f8bba8e674a 100644
--- a/scene/3d/physics/physics_body_3d.h
+++ b/scene/3d/physics/physics_body_3d.h
@@ -67,6 +67,4 @@ public:
 	TypedArray<PhysicsBody3D> get_collision_exceptions();
 	void add_collision_exception_with(Node *p_node); //must be physicsbody
 	void remove_collision_exception_with(Node *p_node);
-
-	PhysicsBody3D();
 };