diff --git a/xs/src/Layer.cpp b/xs/src/Layer.cpp
index fc77f9c3a..69f9fb13a 100644
--- a/xs/src/Layer.cpp
+++ b/xs/src/Layer.cpp
@@ -4,8 +4,8 @@
 namespace Slic3r {
 
 LayerRegion::LayerRegion(Layer *layer, PrintRegion *region)
-:   layer(layer),
-    region(region)
+:   _layer(layer),
+    _region(region)
 {
 }
 
@@ -13,6 +13,18 @@ LayerRegion::~LayerRegion()
 {
 }
 
+Layer*
+LayerRegion::layer()
+{
+    return this->_layer;
+}
+
+PrintRegion*
+LayerRegion::region()
+{
+    return this->_region;
+}
+
 #ifdef SLIC3RXS
 REGISTER_CLASS(LayerRegion, "Layer::Region");
 #endif
@@ -20,8 +32,8 @@ REGISTER_CLASS(LayerRegion, "Layer::Region");
 
 Layer::Layer(int id, PrintObject *object, coordf_t height, coordf_t print_z,
         coordf_t slice_z)
-:   id(id),
-    object(object),
+:   _id(id),
+    _object(object),
     upper_layer(NULL),
     lower_layer(NULL),
     regions(),
@@ -47,6 +59,19 @@ Layer::~Layer()
     this->clear_regions();
 }
 
+int
+Layer::id()
+{
+    return this->_id;
+}
+
+PrintObject*
+Layer::object()
+{
+    return this->_object;
+}
+
+
 size_t
 Layer::region_count()
 {
diff --git a/xs/src/Layer.hpp b/xs/src/Layer.hpp
index bae59ec66..a36d15c48 100644
--- a/xs/src/Layer.hpp
+++ b/xs/src/Layer.hpp
@@ -24,8 +24,8 @@ class LayerRegion
     friend class Layer;
 
     public:
-    Layer *layer;
-    PrintRegion *region;
+    Layer* layer();
+    PrintRegion* region();
 
     // collection of surfaces generated by slicing the original geometry
     // divided by type top/bottom/internal
@@ -51,6 +51,9 @@ class LayerRegion
     ExtrusionEntityCollection fills;
 
     private:
+    Layer *_layer;
+    PrintRegion *_region;
+
     LayerRegion(Layer *layer, PrintRegion *region);
     ~LayerRegion();
 };
@@ -62,8 +65,9 @@ class Layer {
     friend class PrintObject;
 
     public:
-    int id;     // sequential number of layer, 0-based
-    PrintObject *object;
+    int id();
+    PrintObject* object();
+
     Layer *upper_layer;
     Layer *lower_layer;
     LayerRegionPtrs regions;
@@ -84,6 +88,9 @@ class Layer {
     void delete_region(int idx);
 
     protected:
+    int _id;     // sequential number of layer, 0-based
+    PrintObject *_object;
+
     Layer(int id, PrintObject *object, coordf_t height, coordf_t print_z,
         coordf_t slice_z);
     virtual ~Layer();
diff --git a/xs/src/Print.cpp b/xs/src/Print.cpp
index 4f7e8d7e3..686d84e6c 100644
--- a/xs/src/Print.cpp
+++ b/xs/src/Print.cpp
@@ -48,7 +48,7 @@ REGISTER_CLASS(PrintState, "Print::State");
 
 
 PrintRegion::PrintRegion(Print* print)
-:   config(), print(print)
+:   config(), _print(print)
 {
 }
 
@@ -56,10 +56,16 @@ PrintRegion::~PrintRegion()
 {
 }
 
+Print*
+PrintRegion::print()
+{
+    return this->_print;
+}
+
 PrintConfig &
 PrintRegion::print_config()
 {
-    return print->config;
+    return this->_print->config;
 }
 
 #ifdef SLIC3RXS
@@ -69,10 +75,10 @@ REGISTER_CLASS(PrintRegion, "Print::Region");
 
 PrintObject::PrintObject(Print* print, ModelObject* model_object,
         const BoundingBoxf3 &modobj_bbox)
-:   print(print),
-    model_object(model_object)
+:   _print(print),
+    _model_object(model_object)
 {
-    region_volumes.resize(print->regions.size());
+    region_volumes.resize(this->_print->regions.size());
 
     // Compute the translation to be applied to our meshes so that we work with smaller coordinates
     {
@@ -97,6 +103,18 @@ PrintObject::~PrintObject()
 {
 }
 
+Print*
+PrintObject::print()
+{
+    return this->_print;
+}
+
+ModelObject*
+PrintObject::model_object()
+{
+    return this->_model_object;
+}
+
 void
 PrintObject::add_region_volume(int region_id, int volume_id)
 {
diff --git a/xs/src/Print.hpp b/xs/src/Print.hpp
index c1b8ee155..e1b321653 100644
--- a/xs/src/Print.hpp
+++ b/xs/src/Print.hpp
@@ -46,11 +46,13 @@ class PrintRegion
 
     public:
     PrintRegionConfig config;
-    Print* print;
 
+    Print* print();
     PrintConfig &print_config();
 
     private:
+    Print* _print;
+
     PrintRegion(Print* print);
     virtual ~PrintRegion();
 };
@@ -65,9 +67,6 @@ class PrintObject
     friend class Print;
 
     public:
-    Print* print;
-    ModelObject* model_object;
-
     // vector of (vectors of volume ids), indexed by region_id
     std::vector<std::vector<int> > region_volumes;
     Points copies;      // Slic3r::Point objects in scaled G-code coordinates
@@ -89,6 +88,10 @@ class PrintObject
     // TODO: Fill* fill_maker        => (is => 'lazy');
     PrintState _state;
 
+
+    Print* print();
+    ModelObject* model_object();
+
     // adds region_id, too, if necessary
     void add_region_volume(int region_id, int volume_id);
 
@@ -107,6 +110,9 @@ class PrintObject
     void delete_support_layer(int idx);
 
     private:
+    Print* _print;
+    ModelObject* _model_object;
+
     // TODO: call model_object->get_bounding_box() instead of accepting
         // parameter
     PrintObject(Print* print, ModelObject* model_object,
diff --git a/xs/xsp/Layer.xsp b/xs/xsp/Layer.xsp
index c63b3665f..504dbfac9 100644
--- a/xs/xsp/Layer.xsp
+++ b/xs/xsp/Layer.xsp
@@ -9,10 +9,8 @@
 %name{Slic3r::Layer::Region} class LayerRegion {
     // owned by Layer, no constructor/destructor
 
-    Ref<Layer> layer()
-        %code%{ RETVAL = THIS->layer; %};
-    Ref<PrintRegion> region()
-        %code%{ RETVAL = THIS->region; %};
+    Ref<Layer> layer();
+    Ref<PrintRegion> region();
 
     Ref<SurfaceCollection> slices()
         %code%{ RETVAL = &THIS->slices; %};
@@ -33,10 +31,8 @@
 %name{Slic3r::Layer} class Layer {
     // owned by PrintObject, no constructor/destructor
 
-    int id()
-        %code%{ RETVAL = THIS->id; %};
-    Ref<PrintObject> object()
-        %code%{ RETVAL = THIS->object; %};
+    int id();
+    Ref<PrintObject> object();
     Ref<Layer> upper_layer()
         %code%{ RETVAL = THIS->upper_layer; %};
     Ref<Layer> lower_layer()
diff --git a/xs/xsp/Print.xsp b/xs/xsp/Print.xsp
index b48869db1..329fd49a8 100644
--- a/xs/xsp/Print.xsp
+++ b/xs/xsp/Print.xsp
@@ -47,8 +47,7 @@ _constant()
 
     Ref<PrintRegionConfig> config()
         %code%{ RETVAL = &THIS->config; %};
-    Ref<Print> print()
-        %code%{ RETVAL = THIS->print; %};
+    Ref<Print> print();
     Ref<PrintConfig> print_config()
         %code%{ RETVAL = &THIS->print_config(); %};
 };
@@ -64,12 +63,10 @@ _constant()
                 RETVAL = THIS->region_volumes[region_id];
         %};
     int region_count()
-        %code%{ RETVAL = THIS->print->regions.size(); %};
+        %code%{ RETVAL = THIS->print()->regions.size(); %};
 
-    Ref<Print> print()
-        %code%{ RETVAL = THIS->print; %};
-    Ref<ModelObject> model_object()
-        %code%{ RETVAL = THIS->model_object; %};
+    Ref<Print> print();
+    Ref<ModelObject> model_object();
     Ref<PrintObjectConfig> config()
         %code%{ RETVAL = &THIS->config; %};
     Points copies()