diff --git a/resources/shaders/110/gouraud.fs b/resources/shaders/110/gouraud.fs
index 0742f6cc88..cf3163fa37 100644
--- a/resources/shaders/110/gouraud.fs
+++ b/resources/shaders/110/gouraud.fs
@@ -26,8 +26,6 @@ struct SlopeDetection
 uniform vec4 uniform_color;
 uniform SlopeDetection slope;
 
-uniform bool offset_depth_buffer;
-
 #ifdef ENABLE_ENVIRONMENT_MAP
     uniform sampler2D environment_tex;
     uniform bool use_environment_tex;
@@ -78,9 +76,4 @@ void main()
     else
 #endif
         gl_FragColor = vec4(vec3(intensity.y) + color * intensity.x, alpha);
-		
-    // In the support painting gizmo and the seam painting gizmo are painted triangles rendered over the already
-    // rendered object. To resolved z-fighting between previously rendered object and painted triangles, values
-    // inside the depth buffer are offset by small epsilon for painted triangles inside those gizmos.
-    gl_FragDepth = gl_FragCoord.z - (offset_depth_buffer ? EPSILON : 0.0);
 }
diff --git a/resources/shaders/110/mm_contour.fs b/resources/shaders/110/mm_contour.fs
index 14477a59e6..ab656998df 100644
--- a/resources/shaders/110/mm_contour.fs
+++ b/resources/shaders/110/mm_contour.fs
@@ -1,13 +1,8 @@
 #version 110
 
-const float EPSILON = 0.0001;
-
 uniform vec4 uniform_color;
 
 void main()
 {
     gl_FragColor = uniform_color;
-    // Values inside depth buffer for fragments of the contour of a selected area are offset
-    // by small epsilon to solve z-fighting between painted triangles and contour lines.
-    gl_FragDepth = gl_FragCoord.z - EPSILON;
 }
diff --git a/resources/shaders/110/mm_contour.vs b/resources/shaders/110/mm_contour.vs
index d9063f0c70..f75ff1077d 100644
--- a/resources/shaders/110/mm_contour.vs
+++ b/resources/shaders/110/mm_contour.vs
@@ -7,5 +7,8 @@ attribute vec3 v_position;
 
 void main()
 {
-    gl_Position = projection_matrix * view_model_matrix * vec4(v_position, 1.0);
+    // Add small epsilon to z to solve z-fighting between painted triangles and contour lines.
+	vec4 clip_position = projection_matrix * view_model_matrix * vec4(v_position, 1.0);
+	clip_position.z -= 0.00001 * abs(clip_position.w);
+    gl_Position = clip_position;
 }
diff --git a/resources/shaders/140/gouraud.fs b/resources/shaders/140/gouraud.fs
index 225b11dbc0..d87e336321 100644
--- a/resources/shaders/140/gouraud.fs
+++ b/resources/shaders/140/gouraud.fs
@@ -26,8 +26,6 @@ struct SlopeDetection
 uniform vec4 uniform_color;
 uniform SlopeDetection slope;
 
-uniform bool offset_depth_buffer;
-
 #ifdef ENABLE_ENVIRONMENT_MAP
     uniform sampler2D environment_tex;
     uniform bool use_environment_tex;
@@ -80,9 +78,4 @@ void main()
     else
 #endif
         out_color = vec4(vec3(intensity.y) + color * intensity.x, alpha);
-		
-    // In the support painting gizmo and the seam painting gizmo are painted triangles rendered over the already
-    // rendered object. To resolved z-fighting between previously rendered object and painted triangles, values
-    // inside the depth buffer are offset by small epsilon for painted triangles inside those gizmos.
-    gl_FragDepth = gl_FragCoord.z - (offset_depth_buffer ? EPSILON : 0.0);
 }
diff --git a/resources/shaders/140/mm_contour.fs b/resources/shaders/140/mm_contour.fs
index 7797023fa5..28642d53fe 100644
--- a/resources/shaders/140/mm_contour.fs
+++ b/resources/shaders/140/mm_contour.fs
@@ -1,7 +1,5 @@
 #version 140
 
-const float EPSILON = 0.0001;
-
 uniform vec4 uniform_color;
 
 out vec4 out_color;
@@ -9,7 +7,4 @@ out vec4 out_color;
 void main()
 {
     out_color = uniform_color;
-    // Values inside depth buffer for fragments of the contour of a selected area are offset
-    // by small epsilon to solve z-fighting between painted triangles and contour lines.
-    gl_FragDepth = gl_FragCoord.z - EPSILON;
 }
diff --git a/resources/shaders/140/mm_contour.vs b/resources/shaders/140/mm_contour.vs
index 7042671de2..2f6419b8d5 100644
--- a/resources/shaders/140/mm_contour.vs
+++ b/resources/shaders/140/mm_contour.vs
@@ -7,5 +7,8 @@ in vec3 v_position;
 
 void main()
 {
-    gl_Position = projection_matrix * view_model_matrix * vec4(v_position, 1.0);
+    // Add small epsilon to z to solve z-fighting between painted triangles and contour lines.
+	vec4 clip_position = projection_matrix * view_model_matrix * vec4(v_position, 1.0);
+	clip_position.z -= 0.00001 * abs(clip_position.w);
+    gl_Position = clip_position;
 }
diff --git a/resources/shaders/gouraud.fs b/resources/shaders/gouraud.fs
index 511faf4c00..1657fc0513 100644
--- a/resources/shaders/gouraud.fs
+++ b/resources/shaders/gouraud.fs
@@ -26,8 +26,6 @@ struct SlopeDetection
 uniform vec4 uniform_color;
 uniform SlopeDetection slope;
 
-uniform bool offset_depth_buffer;
-
 #ifdef ENABLE_ENVIRONMENT_MAP
     uniform sampler2D environment_tex;
     uniform bool use_environment_tex;
@@ -78,9 +76,4 @@ void main()
     else
 #endif
         gl_FragColor = vec4(vec3(intensity.y) + color * intensity.x, alpha);
-		
-    // In the support painting gizmo and the seam painting gizmo are painted triangles rendered over the already
-    // rendered object. To resolved z-fighting between previously rendered object and painted triangles, values
-    // inside the depth buffer are offset by small epsilon for painted triangles inside those gizmos.
-    gl_FragDepth = gl_FragCoord.z - (offset_depth_buffer ? EPSILON : 0.0);
 }
diff --git a/resources/shaders/mm_contour.fs b/resources/shaders/mm_contour.fs
index 8ccf5b832c..14c18dcf16 100644
--- a/resources/shaders/mm_contour.fs
+++ b/resources/shaders/mm_contour.fs
@@ -1,11 +1,6 @@
 #version 110
 
-const float EPSILON = 0.0001;
-
 void main()
 {
     gl_FragColor = vec4(1.0, 1.0, 1.0, 1.0);
-    // Values inside depth buffer for fragments of the contour of a selected area are offset
-    // by small epsilon to solve z-fighting between painted triangles and contour lines.
-    gl_FragDepth = gl_FragCoord.z - EPSILON;
 }
diff --git a/resources/shaders/mm_contour.vs b/resources/shaders/mm_contour.vs
index d0d3ee42a9..f85fefb80e 100644
--- a/resources/shaders/mm_contour.vs
+++ b/resources/shaders/mm_contour.vs
@@ -2,5 +2,8 @@
 
 void main()
 {
-    gl_Position = ftransform();
+    // Add small epsilon to z to solve z-fighting between painted triangles and contour lines.
+	vec4 clip_position = gl_ModelViewProjectionMatrix * gl_Vertex;
+	clip_position.z -= 0.00001 * abs(clip_position.w);
+    gl_Position = clip_position;
 }
diff --git a/src/slic3r/GUI/GLCanvas3D.cpp b/src/slic3r/GUI/GLCanvas3D.cpp
index f53fd51e66..4af648aa0f 100644
--- a/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/src/slic3r/GUI/GLCanvas3D.cpp
@@ -5333,7 +5333,7 @@ void GLCanvas3D::_picking_pass()
 #if !ENABLE_LEGACY_OPENGL_REMOVAL
         m_camera_clipping_plane = m_gizmos.get_clipping_plane();
         if (m_camera_clipping_plane.is_active()) {
-            ::glClipPlane(GL_CLIP_PLANE0, (GLdouble*)m_camera_clipping_plane.get_data());
+            ::glClipPlane(GL_CLIP_PLANE0, (GLdouble*)m_camera_clipping_plane.get_data().data());
             ::glEnable(GL_CLIP_PLANE0);
         }
 #endif // !ENABLE_LEGACY_OPENGL_REMOVAL
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoMmuSegmentation.cpp b/src/slic3r/GUI/Gizmos/GLGizmoMmuSegmentation.cpp
index 64451fed04..723ce46d59 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoMmuSegmentation.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoMmuSegmentation.cpp
@@ -621,11 +621,7 @@ void TriangleSelectorMmGui::render(ImGuiWrapper *imgui)
 
         auto *contour_shader = wxGetApp().get_shader("mm_contour");
         contour_shader->start_using();
-
-        glsafe(::glDepthFunc(GL_LEQUAL));
         m_paint_contour.render();
-        glsafe(::glDepthFunc(GL_LESS));
-
         contour_shader->stop_using();
     }
 #endif // ENABLE_LEGACY_OPENGL_REMOVAL
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoPainterBase.cpp b/src/slic3r/GUI/Gizmos/GLGizmoPainterBase.cpp
index a3128b9620..ea818b6f74 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoPainterBase.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoPainterBase.cpp
@@ -316,9 +316,11 @@ void GLGizmoPainterBase::render_cursor_sphere(const Transform3d& trafo) const
 #endif // ENABLE_LEGACY_OPENGL_REMOVAL
     }
 
+#if ENABLE_LEGACY_OPENGL_REMOVAL
     GLShaderProgram* shader = wxGetApp().get_shader("flat");
     if (shader == nullptr)
         return;
+#endif // ENABLE_LEGACY_OPENGL_REMOVAL
 
     const Transform3d complete_scaling_matrix_inverse = Geometry::Transformation(trafo).get_matrix(true, true, false, true).inverse();
     const bool is_left_handed = Geometry::Transformation(trafo).is_left_handed();
@@ -948,8 +950,6 @@ void TriangleSelectorGUI::render(ImGuiWrapper* imgui)
 
     assert(shader->get_name() == "gouraud");
 
-    ScopeGuard guard([shader]() { if (shader) shader->set_uniform("offset_depth_buffer", false);});
-    shader->set_uniform("offset_depth_buffer", true);
     for (auto iva : {std::make_pair(&m_iva_enforcers, enforcers_color),
                      std::make_pair(&m_iva_blockers, blockers_color)}) {
 #if ENABLE_LEGACY_OPENGL_REMOVAL
@@ -993,11 +993,7 @@ void TriangleSelectorGUI::render(ImGuiWrapper* imgui)
 
         auto *contour_shader = wxGetApp().get_shader("mm_contour");
         contour_shader->start_using();
-
-        glsafe(::glDepthFunc(GL_LEQUAL));
         m_paint_contour.render();
-        glsafe(::glDepthFunc(GL_LESS));
-
         contour_shader->stop_using();
     }
 #endif // ENABLE_LEGACY_OPENGL_REMOVAL
@@ -1040,6 +1036,9 @@ void TriangleSelectorGUI::update_render_data()
         iva.release_geometry();
 #endif // ENABLE_LEGACY_OPENGL_REMOVAL
 
+    // small value used to offset triangles along their normal to avoid z-fighting
+    static const float offset = 0.001f;
+
     for (const Triangle &tr : m_triangles) {
         if (!tr.valid() || tr.is_split() || (tr.get_state() == EnforcerBlockerType::NONE && !tr.is_selected_by_seed_fill()))
             continue;
@@ -1063,15 +1062,17 @@ void TriangleSelectorGUI::update_render_data()
         //FIXME the normal may likely be pulled from m_triangle_selectors, but it may not be worth the effort
         // or the current implementation may be more cache friendly.
         const Vec3f           n   = (v1 - v0).cross(v2 - v1).normalized();
+        // small value used to offset triangles along their normal to avoid z-fighting
+        const Vec3f    offset_n   = offset * n;
 #if ENABLE_LEGACY_OPENGL_REMOVAL
-        iva.add_vertex(v0, n);
-        iva.add_vertex(v1, n);
-        iva.add_vertex(v2, n);
+        iva.add_vertex(v0 + offset_n, n);
+        iva.add_vertex(v1 + offset_n, n);
+        iva.add_vertex(v2 + offset_n, n);
         iva.add_triangle((unsigned int)cnt, (unsigned int)cnt + 1, (unsigned int)cnt + 2);
 #else
-        iva.push_geometry(v0, n);
-        iva.push_geometry(v1, n);
-        iva.push_geometry(v2, n);
+        iva.push_geometry(v0 + offset_n, n);
+        iva.push_geometry(v1 + offset_n, n);
+        iva.push_geometry(v2 + offset_n, n);
         iva.push_triangle(cnt, cnt + 1, cnt + 2);
 #endif // ENABLE_LEGACY_OPENGL_REMOVAL
         cnt += 3;
@@ -1383,10 +1384,7 @@ void TriangleSelectorGUI::render_paint_contour(const Transform3d& matrix)
         contour_shader->set_uniform("view_model_matrix", camera.get_view_matrix() * matrix);
         contour_shader->set_uniform("projection_matrix", camera.get_projection_matrix());
 
-        glsafe(::glDepthFunc(GL_LEQUAL));
         m_paint_contour.render();
-        glsafe(::glDepthFunc(GL_LESS));
-
         contour_shader->stop_using();
     }