diff --git a/src/libslic3r/Model.cpp b/src/libslic3r/Model.cpp
index 235c35797..8eb5bb389 100644
--- a/src/libslic3r/Model.cpp
+++ b/src/libslic3r/Model.cpp
@@ -956,9 +956,22 @@ void ModelObject::center_around_origin(bool include_modifiers)
 
 void ModelObject::ensure_on_bed(bool allow_negative_z)
 {
-    const double min_z = get_min_z();
-    if (!allow_negative_z || min_z > SINKING_Z_THRESHOLD)
-        translate_instances({ 0.0, 0.0, -min_z });
+    double z_offset = 0.0;
+
+    if (allow_negative_z) {
+        if (volumes.size() == 1)
+            z_offset = -get_min_z();
+        else {
+            const double max_z = get_max_z();
+            if (max_z < SINKING_MIN_Z_THRESHOLD)
+                z_offset = SINKING_MIN_Z_THRESHOLD - max_z;
+        }
+    }
+    else
+        z_offset = -get_min_z();
+
+    if (z_offset != 0.0)
+        translate_instances(z_offset * Vec3d::UnitZ());
 }
 
 void ModelObject::translate_instances(const Vec3d& vector)
@@ -1429,6 +1442,19 @@ double ModelObject::get_min_z() const
     }
 }
 
+double ModelObject::get_max_z() const
+{
+    if (instances.empty())
+        return 0.0;
+    else {
+        double max_z = -DBL_MAX;
+        for (size_t i = 0; i < instances.size(); ++i) {
+            max_z = std::max(max_z, get_instance_max_z(i));
+        }
+        return max_z;
+    }
+}
+
 double ModelObject::get_instance_min_z(size_t instance_idx) const
 {
     double min_z = DBL_MAX;
@@ -1450,6 +1476,27 @@ double ModelObject::get_instance_min_z(size_t instance_idx) const
     return min_z + inst->get_offset(Z);
 }
 
+double ModelObject::get_instance_max_z(size_t instance_idx) const
+{
+    double max_z = -DBL_MAX;
+
+    const ModelInstance* inst = instances[instance_idx];
+    const Transform3d& mi = inst->get_matrix(true);
+
+    for (const ModelVolume* v : volumes) {
+        if (!v->is_model_part())
+            continue;
+
+        const Transform3d mv = mi * v->get_matrix();
+        const TriangleMesh& hull = v->get_convex_hull();
+        for (const stl_facet& facet : hull.stl.facet_start)
+            for (int i = 0; i < 3; ++i)
+                max_z = std::max(max_z, (mv * facet.vertex[i].cast<double>()).z());
+    }
+
+    return max_z + inst->get_offset(Z);
+}
+
 unsigned int ModelObject::check_instances_print_volume_state(const BoundingBoxf3& print_volume)
 {
     unsigned int num_printable = 0;
diff --git a/src/libslic3r/Model.hpp b/src/libslic3r/Model.hpp
index 1dd16ee91..25f19e792 100644
--- a/src/libslic3r/Model.hpp
+++ b/src/libslic3r/Model.hpp
@@ -358,7 +358,9 @@ public:
     void bake_xy_rotation_into_meshes(size_t instance_idx);
 
     double get_min_z() const;
+    double get_max_z() const;
     double get_instance_min_z(size_t instance_idx) const;
+    double get_instance_max_z(size_t instance_idx) const;
 
     // Called by Print::validate() from the UI thread.
     unsigned int check_instances_print_volume_state(const BoundingBoxf3& print_volume);
diff --git a/src/slic3r/GUI/GUI_ObjectList.cpp b/src/slic3r/GUI/GUI_ObjectList.cpp
index 1e290beae..23ce819dd 100644
--- a/src/slic3r/GUI/GUI_ObjectList.cpp
+++ b/src/slic3r/GUI/GUI_ObjectList.cpp
@@ -1920,16 +1920,15 @@ bool ObjectList::del_subobject_from_object(const int obj_idx, const int idx, con
             if (vol->is_model_part())
                 ++solid_cnt;
         if (volume->is_model_part() && solid_cnt == 1) {
-            Slic3r::GUI::show_error(nullptr, _(L("From Object List You can't delete the last solid part from object.")));
+            Slic3r::GUI::show_error(nullptr, _L("From Object List You can't delete the last solid part from object."));
             return false;
         }
 
-        take_snapshot(_(L("Delete Subobject")));
+        take_snapshot(_L("Delete Subobject"));
 
         object->delete_volume(idx);
 
-        if (object->volumes.size() == 1)
-        {
+        if (object->volumes.size() == 1) {
             const auto last_volume = object->volumes[0];
             if (!last_volume->config.empty()) {
                 object->config.apply(last_volume->config);
@@ -1948,11 +1947,11 @@ bool ObjectList::del_subobject_from_object(const int obj_idx, const int idx, con
     }
     else if (type == itInstance) {
         if (object->instances.size() == 1) {
-            Slic3r::GUI::show_error(nullptr, _(L("Last instance of an object cannot be deleted.")));
+            Slic3r::GUI::show_error(nullptr, _L("Last instance of an object cannot be deleted."));
             return false;
         }
 
-        take_snapshot(_(L("Delete Instance")));
+        take_snapshot(_L("Delete Instance"));
         object->delete_instance(idx);
     }
     else
diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index 60215484b..72b2c5909 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -6200,8 +6200,7 @@ void Plater::changed_object(int obj_idx)
     if (obj_idx < 0)
         return;
     // recenter and re - align to Z = 0
-    auto model_object = p->model.objects[obj_idx];
-    model_object->ensure_on_bed(this->p->printer_technology != ptSLA);
+    p->model.objects[obj_idx]->ensure_on_bed(p->printer_technology != ptSLA);
     if (this->p->printer_technology == ptSLA) {
         // Update the SLAPrint from the current Model, so that the reload_scene()
         // pulls the correct data, update the 3D scene.