diff --git a/src/slic3r/GUI/GLCanvas3D.cpp b/src/slic3r/GUI/GLCanvas3D.cpp
index a8826402f..6e4be1aac 100644
--- a/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/src/slic3r/GUI/GLCanvas3D.cpp
@@ -1931,7 +1931,7 @@ void GLCanvas3D::render()
 }
 
 #if ENABLE_THUMBNAIL_GENERATOR
-void GLCanvas3D::render_thumbnail(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only, bool parts_only, bool show_bed, bool transparent_background)
+void GLCanvas3D::render_thumbnail(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only, bool parts_only, bool show_bed, bool transparent_background) const
 {
     switch (GLCanvas3DManager::get_framebuffers_type())
     {
@@ -3831,7 +3831,7 @@ static bool string_getter(const bool is_undo, int idx, const char** out_text)
     return wxGetApp().plater()->undo_redo_string_getter(is_undo, idx, out_text);
 }
 
-void GLCanvas3D::_render_undo_redo_stack(const bool is_undo, float pos_x)
+void GLCanvas3D::_render_undo_redo_stack(const bool is_undo, float pos_x) const
 {
     ImGuiWrapper* imgui = wxGetApp().imgui();
 
@@ -3885,7 +3885,7 @@ static void debug_output_thumbnail(const ThumbnailData& thumbnail_data)
 }
 #endif // ENABLE_THUMBNAIL_GENERATOR_DEBUG_OUTPUT
 
-void GLCanvas3D::_render_thumbnail_internal(ThumbnailData& thumbnail_data, bool printable_only, bool parts_only, bool show_bed, bool transparent_background)
+void GLCanvas3D::_render_thumbnail_internal(ThumbnailData& thumbnail_data, bool printable_only, bool parts_only, bool show_bed, bool transparent_background) const
 {
     auto is_visible = [](const GLVolume& v) -> bool
     {
@@ -3975,7 +3975,7 @@ void GLCanvas3D::_render_thumbnail_internal(ThumbnailData& thumbnail_data, bool
         glsafe(::glClearColor(1.0f, 1.0f, 1.0f, 1.0f));
 }
 
-void GLCanvas3D::_render_thumbnail_framebuffer(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only, bool parts_only, bool show_bed, bool transparent_background)
+void GLCanvas3D::_render_thumbnail_framebuffer(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only, bool parts_only, bool show_bed, bool transparent_background) const
 {
     thumbnail_data.set(w, h);
     if (!thumbnail_data.is_valid())
@@ -4079,7 +4079,7 @@ void GLCanvas3D::_render_thumbnail_framebuffer(ThumbnailData& thumbnail_data, un
         glsafe(::glDisable(GL_MULTISAMPLE));
 }
 
-void GLCanvas3D::_render_thumbnail_framebuffer_ext(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only, bool parts_only, bool show_bed, bool transparent_background)
+void GLCanvas3D::_render_thumbnail_framebuffer_ext(ThumbnailData & thumbnail_data, unsigned int w, unsigned int h, bool printable_only, bool parts_only, bool show_bed, bool transparent_background) const
 {
     thumbnail_data.set(w, h);
     if (!thumbnail_data.is_valid())
@@ -4183,7 +4183,7 @@ void GLCanvas3D::_render_thumbnail_framebuffer_ext(ThumbnailData& thumbnail_data
         glsafe(::glDisable(GL_MULTISAMPLE));
 }
 
-void GLCanvas3D::_render_thumbnail_legacy(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only, bool parts_only, bool show_bed, bool transparent_background)
+void GLCanvas3D::_render_thumbnail_legacy(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only, bool parts_only, bool show_bed, bool transparent_background) const
 {
     // check that thumbnail size does not exceed the default framebuffer size
     const Size& cnv_size = get_canvas_size();
diff --git a/src/slic3r/GUI/GLCanvas3D.hpp b/src/slic3r/GUI/GLCanvas3D.hpp
index b26111ced..2ff65052a 100644
--- a/src/slic3r/GUI/GLCanvas3D.hpp
+++ b/src/slic3r/GUI/GLCanvas3D.hpp
@@ -477,7 +477,7 @@ private:
     RenderStats m_render_stats;
 #endif // ENABLE_RENDER_STATISTICS
 
-    int m_imgui_undo_redo_hovered_pos{ -1 };
+    mutable int m_imgui_undo_redo_hovered_pos{ -1 };
     int m_selected_extruder;
 
 public:
@@ -569,7 +569,7 @@ public:
 #if ENABLE_THUMBNAIL_GENERATOR
     // printable_only == false -> render also non printable volumes as grayed
     // parts_only == false -> render also sla support and pad
-    void render_thumbnail(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only, bool parts_only, bool show_bed, bool transparent_background);
+    void render_thumbnail(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only, bool parts_only, bool show_bed, bool transparent_background) const;
 #endif // ENABLE_THUMBNAIL_GENERATOR
 
     void select_all();
@@ -724,15 +724,15 @@ private:
 #endif // ENABLE_SHOW_CAMERA_TARGET
     void _render_sla_slices() const;
     void _render_selection_sidebar_hints() const;
-    void _render_undo_redo_stack(const bool is_undo, float pos_x);
+    void _render_undo_redo_stack(const bool is_undo, float pos_x) const;
 #if ENABLE_THUMBNAIL_GENERATOR
-    void _render_thumbnail_internal(ThumbnailData& thumbnail_data, bool printable_only, bool parts_only, bool show_bed, bool transparent_background);
+    void _render_thumbnail_internal(ThumbnailData& thumbnail_data, bool printable_only, bool parts_only, bool show_bed, bool transparent_background) const;
     // render thumbnail using an off-screen framebuffer
-    void _render_thumbnail_framebuffer(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only, bool parts_only, bool show_bed, bool transparent_background);
+    void _render_thumbnail_framebuffer(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only, bool parts_only, bool show_bed, bool transparent_background) const;
     // render thumbnail using an off-screen framebuffer when GLEW_EXT_framebuffer_object is supported
-    void _render_thumbnail_framebuffer_ext(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only, bool parts_only, bool show_bed, bool transparent_background);
+    void _render_thumbnail_framebuffer_ext(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only, bool parts_only, bool show_bed, bool transparent_background) const;
     // render thumbnail using the default framebuffer
-    void _render_thumbnail_legacy(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only, bool parts_only, bool show_bed, bool transparent_background);
+    void _render_thumbnail_legacy(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only, bool parts_only, bool show_bed, bool transparent_background) const;
 #endif // ENABLE_THUMBNAIL_GENERATOR
 
     void _update_volumes_hover_state() const;