diff --git a/src/libslic3r/Technologies.hpp b/src/libslic3r/Technologies.hpp
index b06fa4ad08..8da21d56a6 100644
--- a/src/libslic3r/Technologies.hpp
+++ b/src/libslic3r/Technologies.hpp
@@ -41,8 +41,6 @@
 //====================
 #define ENABLE_2_4_0_ALPHA1 1
 
-// Enable drawing contours, at cut level, for sinking volumes
-#define ENABLE_SINKING_CONTOURS (1 && ENABLE_2_4_0_ALPHA1)
 // Enable implementation of retract acceleration in gcode processor
 #define ENABLE_RETRACT_ACCELERATION (1 && ENABLE_2_4_0_ALPHA1)
 // Enable the fix for exporting and importing to/from 3mf file of mirrored volumes
diff --git a/src/slic3r/GUI/3DScene.cpp b/src/slic3r/GUI/3DScene.cpp
index c758468300..0760514e60 100644
--- a/src/slic3r/GUI/3DScene.cpp
+++ b/src/slic3r/GUI/3DScene.cpp
@@ -9,9 +9,7 @@
 #include "3DScene.hpp"
 #include "GLShader.hpp"
 #include "GUI_App.hpp"
-#if ENABLE_ENVIRONMENT_MAP || ENABLE_SINKING_CONTOURS
 #include "Plater.hpp"
-#endif // ENABLE_ENVIRONMENT_MAP || ENABLE_SINKING_CONTOURS
 
 #include "libslic3r/ExtrusionEntity.hpp"
 #include "libslic3r/ExtrusionEntityCollection.hpp"
@@ -25,9 +23,7 @@
 #include "libslic3r/AppConfig.hpp"
 #include "libslic3r/PresetBundle.hpp"
 #include "libslic3r/ClipperUtils.hpp"
-#if ENABLE_SINKING_CONTOURS
 #include "libslic3r/Tesselate.hpp"
-#endif // ENABLE_SINKING_CONTOURS
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -293,7 +289,6 @@ void GLIndexedVertexArray::render(
     glsafe(::glBindBuffer(GL_ARRAY_BUFFER, 0));
 }
 
-#if ENABLE_SINKING_CONTOURS
 const float GLVolume::SinkingContours::HalfWidth = 0.25f;
 
 void GLVolume::SinkingContours::render()
@@ -362,7 +357,6 @@ void GLVolume::SinkingContours::update()
     else
         m_model.reset();
 }
-#endif // ENABLE_SINKING_CONTOURS
 
 const std::array<float, 4> GLVolume::SELECTED_COLOR = { 0.0f, 1.0f, 0.0f, 1.0f };
 const std::array<float, 4> GLVolume::HOVER_SELECT_COLOR = { 0.4f, 0.9f, 0.1f, 1.0f };
@@ -384,9 +378,7 @@ GLVolume::GLVolume(float r, float g, float b, float a)
     : m_transformed_bounding_box_dirty(true)
     , m_sla_shift_z(0.0)
     , m_transformed_convex_hull_bounding_box_dirty(true)
-#if ENABLE_SINKING_CONTOURS
     , m_sinking_contours(*this)
-#endif // ENABLE_SINKING_CONTOURS
     // geometry_id == 0 -> invalid
     , geometry_id(std::pair<size_t, size_t>(0, 0))
     , extruder_id(0)
@@ -404,9 +396,7 @@ GLVolume::GLVolume(float r, float g, float b, float a)
     , force_transparent(false)
     , force_native_color(false)
     , force_neutral_color(false)
-#if ENABLE_SINKING_CONTOURS
     , force_sinking_contours(false)
-#endif // ENABLE_SINKING_CONTOURS
     , tverts_range(0, size_t(-1))
     , qverts_range(0, size_t(-1))
 {
@@ -610,12 +600,10 @@ bool GLVolume::is_below_printbed() const
     return transformed_convex_hull_bounding_box().max.z() < 0.0;
 }
 
-#if ENABLE_SINKING_CONTOURS
 void GLVolume::render_sinking_contours()
 {
     m_sinking_contours.render();
 }
-#endif // ENABLE_SINKING_CONTOURS
 
 std::vector<int> GLVolumeCollection::load_object(
     const ModelObject       *model_object,
@@ -839,11 +827,9 @@ GLVolumeWithIdAndZList volumes_to_render(const GLVolumePtrs& volumes, GLVolumeCo
 
 void GLVolumeCollection::render(GLVolumeCollection::ERenderType type, bool disable_cullface, const Transform3d& view_matrix, std::function<bool(const GLVolume&)> filter_func) const
 {
-#if ENABLE_SINKING_CONTOURS
     GLVolumeWithIdAndZList to_render = volumes_to_render(volumes, type, view_matrix, filter_func);
     if (to_render.empty())
         return;
-#endif // ENABLE_SINKING_CONTOURS
 
     GLShaderProgram* shader = GUI::wxGetApp().get_current_shader();
     if (shader == nullptr)
@@ -858,7 +844,6 @@ void GLVolumeCollection::render(GLVolumeCollection::ERenderType type, bool disab
     if (disable_cullface)
         glsafe(::glDisable(GL_CULL_FACE));
 
-#if ENABLE_SINKING_CONTOURS
     for (GLVolumeWithIdAndZ& volume : to_render) {
         volume.first->set_render_color();
 
@@ -908,7 +893,7 @@ void GLVolumeCollection::render(GLVolumeCollection::ERenderType type, bool disab
         glsafe(::glDisableClientState(GL_NORMAL_ARRAY));
     }
 
-    if (m_show_sinking_contours)
+    if (m_show_sinking_contours) {
         for (GLVolumeWithIdAndZ& volume : to_render) {
             // render sinking contours of hovered/displaced volumes
             if (volume.first->is_sinking() && !volume.first->is_below_printbed() &&
@@ -920,48 +905,8 @@ void GLVolumeCollection::render(GLVolumeCollection::ERenderType type, bool disab
                 shader->start_using();
             }
         }
-#else
-    glsafe(::glEnableClientState(GL_VERTEX_ARRAY));
-    glsafe(::glEnableClientState(GL_NORMAL_ARRAY));
- 
-    shader->set_uniform("print_box.min", m_print_box_min, 3);
-    shader->set_uniform("print_box.max", m_print_box_max, 3);
-    shader->set_uniform("z_range", m_z_range, 2);
-    shader->set_uniform("clipping_plane", m_clipping_plane, 4);
-    shader->set_uniform("slope.normal_z", m_slope.normal_z);
-
-#if ENABLE_ENVIRONMENT_MAP
-    unsigned int environment_texture_id = GUI::wxGetApp().plater()->get_environment_texture_id();
-    bool use_environment_texture = environment_texture_id > 0 && GUI::wxGetApp().app_config->get("use_environment_map") == "1";
-    shader->set_uniform("use_environment_tex", use_environment_texture);
-    if (use_environment_texture)
-        glsafe(::glBindTexture(GL_TEXTURE_2D, environment_texture_id));
-#endif // ENABLE_ENVIRONMENT_MAP
-    glcheck();
-
-    GLVolumeWithIdAndZList to_render = volumes_to_render(this->volumes, type, view_matrix, filter_func);
-    for (GLVolumeWithIdAndZ& volume : to_render) {
-        volume.first->set_render_color();
-        shader->set_uniform("uniform_color", volume.first->render_color);
-        shader->set_uniform("print_box.actived", volume.first->shader_outside_printer_detection_enabled);
-        shader->set_uniform("print_box.volume_world_matrix", volume.first->world_matrix());
-        shader->set_uniform("slope.actived", m_slope.active && !volume.first->is_modifier && !volume.first->is_wipe_tower);
-        shader->set_uniform("slope.volume_world_normal_matrix", static_cast<Matrix3f>(volume.first->world_matrix().matrix().block(0, 0, 3, 3).inverse().transpose().cast<float>()));
-        volume.first->render();
     }
 
-#if ENABLE_ENVIRONMENT_MAP
-    if (use_environment_texture)
-        glsafe(::glBindTexture(GL_TEXTURE_2D, 0));
-#endif // ENABLE_ENVIRONMENT_MAP
-
-    glsafe(::glBindBuffer(GL_ARRAY_BUFFER, 0));
-    glsafe(::glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0));
-
-    glsafe(::glDisableClientState(GL_VERTEX_ARRAY));
-    glsafe(::glDisableClientState(GL_NORMAL_ARRAY));
-#endif // ENABLE_SINKING_CONTOURS
-
     if (disable_cullface)
         glsafe(::glEnable(GL_CULL_FACE));
 
diff --git a/src/slic3r/GUI/3DScene.hpp b/src/slic3r/GUI/3DScene.hpp
index c90af7d4ba..1fde1697ea 100644
--- a/src/slic3r/GUI/3DScene.hpp
+++ b/src/slic3r/GUI/3DScene.hpp
@@ -8,9 +8,7 @@
 #include "libslic3r/Utils.hpp"
 #include "libslic3r/Geometry.hpp"
 
-#if ENABLE_SINKING_CONTOURS
 #include "GLModel.hpp"
-#endif // ENABLE_SINKING_CONTOURS
 
 #include <functional>
 
@@ -260,9 +258,7 @@ public:
     enum EHoverState : unsigned char
     {
         HS_None,
-#if ENABLE_SINKING_CONTOURS
         HS_Hover,
-#endif // ENABLE_SINKING_CONTOURS
         HS_Select,
         HS_Deselect
     };
@@ -287,7 +283,6 @@ private:
     // Whether or not is needed to recalculate the transformed convex hull bounding box.
     bool          m_transformed_convex_hull_bounding_box_dirty;
 
-#if ENABLE_SINKING_CONTOURS
     class SinkingContours
     {
         static const float HalfWidth;
@@ -305,7 +300,6 @@ private:
     };
 
     SinkingContours m_sinking_contours;
-#endif // ENABLE_SINKING_CONTOURS
 
 public:
     // Color of the triangles / quads held by this volume.
@@ -367,10 +361,8 @@ public:
 	    bool                force_native_color : 1;
         // Whether or not render this volume in neutral
         bool                force_neutral_color : 1;
-#if ENABLE_SINKING_CONTOURS
         // Whether or not to force rendering of sinking contours
         bool                force_sinking_contours : 1;
-#endif // ENABLE_SINKING_CONTOURS
     };
 
     // Is mouse or rectangle selection over this object to select/deselect it ?
@@ -499,9 +491,7 @@ public:
 
     bool                is_sinking() const;
     bool                is_below_printbed() const;
-#if ENABLE_SINKING_CONTOURS
     void                render_sinking_contours();
-#endif // ENABLE_SINKING_CONTOURS
 
     // Return an estimate of the memory consumed by this class.
     size_t 				cpu_memory_used() const { 
diff --git a/src/slic3r/GUI/GLCanvas3D.cpp b/src/slic3r/GUI/GLCanvas3D.cpp
index 3c518ef2bf..83b907f013 100644
--- a/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/src/slic3r/GUI/GLCanvas3D.cpp
@@ -2926,7 +2926,6 @@ void GLCanvas3D::on_mouse(wxMouseEvent& evt)
         return;
     }
 
-#if ENABLE_SINKING_CONTOURS
     for (GLVolume* volume : m_volumes.volumes) {
         volume->force_sinking_contours = false;
     }
@@ -2938,7 +2937,6 @@ void GLCanvas3D::on_mouse(wxMouseEvent& evt)
         }
         m_dirty = true;
     };
-#endif // ENABLE_SINKING_CONTOURS
 
     if (m_gizmos.on_mouse(evt)) {
         if (wxWindow::FindFocus() != m_canvas)
@@ -2964,7 +2962,6 @@ void GLCanvas3D::on_mouse(wxMouseEvent& evt)
             default: { break; }
             }
         }
-#if ENABLE_SINKING_CONTOURS
         else if (evt.Dragging()) {
             switch (m_gizmos.get_current_type())
             {
@@ -2978,7 +2975,6 @@ void GLCanvas3D::on_mouse(wxMouseEvent& evt)
             default: { break; }
             }
         }
-#endif // ENABLE_SINKING_CONTOURS
 
         return;
     }
@@ -3288,10 +3284,8 @@ void GLCanvas3D::on_mouse(wxMouseEvent& evt)
     else
         evt.Skip();
 
-#if ENABLE_SINKING_CONTOURS
     if (m_moving)
         show_sinking_contours();
-#endif // ENABLE_SINKING_CONTOURS
 
 #ifdef __WXMSW__
 	if (on_enter_workaround)
@@ -5648,11 +5642,8 @@ void GLCanvas3D::_update_volumes_hover_state()
                 }
             }
         }
-#if ENABLE_SINKING_CONTOURS
         else if (volume.selected)
             volume.hover = GLVolume::HS_Hover;
-#endif // ENABLE_SINKING_CONTOURS
-
     }
 }
 
diff --git a/src/slic3r/GUI/GLModel.cpp b/src/slic3r/GUI/GLModel.cpp
index 0fe6c8546c..298fb21b0b 100644
--- a/src/slic3r/GUI/GLModel.cpp
+++ b/src/slic3r/GUI/GLModel.cpp
@@ -7,9 +7,7 @@
 
 #include "libslic3r/TriangleMesh.hpp"
 #include "libslic3r/Model.hpp"
-#if ENABLE_SINKING_CONTOURS
 #include "libslic3r/Polygon.hpp"
-#endif // ENABLE_SINKING_CONTOURS
 
 #include <boost/filesystem/operations.hpp>
 #include <boost/algorithm/string/predicate.hpp>
@@ -116,7 +114,6 @@ void GLModel::init_from(const indexed_triangle_set& its)
     this->init_from(its, bounding_box(its));
 }
 
-#if ENABLE_SINKING_CONTOURS
 void GLModel::init_from(const Polygons& polygons, float z)
 {
     auto append_polygon = [](const Polygon& polygon, float z, GUI::GLModel::InitializationData& data) {
@@ -143,7 +140,6 @@ void GLModel::init_from(const Polygons& polygons, float z)
     }
     init_from(init_data);
 }
-#endif // ENABLE_SINKING_CONTOURS
 
 bool GLModel::init_from_file(const std::string& filename)
 {
diff --git a/src/slic3r/GUI/GLModel.hpp b/src/slic3r/GUI/GLModel.hpp
index 95be6dca1f..1258da1cb6 100644
--- a/src/slic3r/GUI/GLModel.hpp
+++ b/src/slic3r/GUI/GLModel.hpp
@@ -9,10 +9,8 @@
 namespace Slic3r {
 
 class TriangleMesh;
-#if ENABLE_SINKING_CONTOURS
 class Polygon;
 using Polygons = std::vector<Polygon>;
-#endif // ENABLE_SINKING_CONTOURS
 
 namespace GUI {
 
@@ -72,9 +70,7 @@ namespace GUI {
         void init_from(const InitializationData& data);
         void init_from(const indexed_triangle_set& its, const BoundingBoxf3& bbox);
         void init_from(const indexed_triangle_set& its);
-#if ENABLE_SINKING_CONTOURS
         void init_from(const Polygons& polygons, float z);
-#endif // ENABLE_SINKING_CONTOURS
         bool init_from_file(const std::string& filename);
 
         // if entity_id == -1 set the color of all entities
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoCut.cpp b/src/slic3r/GUI/Gizmos/GLGizmoCut.cpp
index 3dcb9e2b10..e4cbd77d41 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoCut.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoCut.cpp
@@ -16,9 +16,7 @@
 #include "slic3r/GUI/GUI_ObjectManipulation.hpp"
 #include "libslic3r/AppConfig.hpp"
 #include "libslic3r/Model.hpp"
-#if ENABLE_SINKING_CONTOURS
 #include "libslic3r/TriangleMeshSlicer.hpp"
-#endif // ENABLE_SINKING_CONTOURS
 
 namespace Slic3r {
 namespace GUI {
@@ -92,9 +90,7 @@ void GLGizmoCut::on_render()
     m_max_z = box.max.z();
     set_cut_z(m_cut_z);
 
-#if ENABLE_SINKING_CONTOURS
     update_contours();
-#endif // ENABLE_SINKING_CONTOURS
 
     const float min_x = box.min.x() - Margin;
     const float max_x = box.max.x() + Margin;
@@ -143,13 +139,11 @@ void GLGizmoCut::on_render()
 
     shader->stop_using();
 
-#if ENABLE_SINKING_CONTOURS
     glsafe(::glPushMatrix());
     glsafe(::glTranslated(m_cut_contours.shift.x(), m_cut_contours.shift.y(), m_cut_contours.shift.z()));
     glsafe(::glLineWidth(2.0f));
     m_cut_contours.contours.render();
     glsafe(::glPopMatrix());
-#endif // ENABLE_SINKING_CONTOURS
 }
 
 void GLGizmoCut::on_render_for_picking()
@@ -275,7 +269,6 @@ BoundingBoxf3 GLGizmoCut::bounding_box() const
     return ret;
 }
 
-#if ENABLE_SINKING_CONTOURS
 void GLGizmoCut::update_contours()
 {
     const Selection& selection = m_parent.get_selection();
@@ -315,7 +308,6 @@ void GLGizmoCut::update_contours()
     else
         m_cut_contours.contours.reset();
 }
-#endif // ENABLE_SINKING_CONTOURS
 
 } // namespace GUI
 } // namespace Slic3r
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoCut.hpp b/src/slic3r/GUI/Gizmos/GLGizmoCut.hpp
index b691357afa..4007f89d47 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoCut.hpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoCut.hpp
@@ -2,11 +2,9 @@
 #define slic3r_GLGizmoCut_hpp_
 
 #include "GLGizmoBase.hpp"
-#if ENABLE_SINKING_CONTOURS
 #include "slic3r/GUI/GLModel.hpp"
 #include "libslic3r/TriangleMesh.hpp"
 #include "libslic3r/ObjectID.hpp"
-#endif // ENABLE_SINKING_CONTOURS
 
 namespace Slic3r {
 namespace GUI {
@@ -26,7 +24,6 @@ class GLGizmoCut : public GLGizmoBase
     bool m_keep_lower{ true };
     bool m_rotate_lower{ false };
 
-#if ENABLE_SINKING_CONTOURS
     struct CutContours
     {
         TriangleMesh mesh;
@@ -39,7 +36,6 @@ class GLGizmoCut : public GLGizmoBase
     };
 
     CutContours m_cut_contours;
-#endif // ENABLE_SINKING_CONTOURS
 
 public:
     GLGizmoCut(GLCanvas3D& parent, const std::string& icon_filename, unsigned int sprite_id);
@@ -66,9 +62,7 @@ private:
     void perform_cut(const Selection& selection);
     double calc_projection(const Linef3& mouse_ray) const;
     BoundingBoxf3 bounding_box() const;
-#if ENABLE_SINKING_CONTOURS
     void update_contours();
-#endif // ENABLE_SINKING_CONTOURS
 };
 
 } // namespace GUI