diff --git a/src/libslic3r/Technologies.hpp b/src/libslic3r/Technologies.hpp
index 303ffe927..369996fba 100644
--- a/src/libslic3r/Technologies.hpp
+++ b/src/libslic3r/Technologies.hpp
@@ -59,6 +59,8 @@
 #define ENABLE_EXTENDED_M73_LINES (1 && ENABLE_VALIDATE_CUSTOM_GCODE)
 // Enable a modified version of automatic downscale on load of objects too big
 #define ENABLE_MODIFIED_DOWNSCALE_ON_LOAD_OBJECTS_TOO_BIG (1 && ENABLE_2_4_0_ALPHA0)
+// Enable to push object instances under the bed
+#define ENABLE_ALLOW_NEGATIVE_Z (1 && ENABLE_2_4_0_ALPHA0)
 
 
 #endif // _prusaslicer_technologies_h_
diff --git a/src/slic3r/GUI/GLCanvas3D.cpp b/src/slic3r/GUI/GLCanvas3D.cpp
index 97038723b..59a4a62a4 100644
--- a/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/src/slic3r/GUI/GLCanvas3D.cpp
@@ -3572,12 +3572,25 @@ void GLCanvas3D::do_move(const std::string& snapshot_type)
             wipe_tower_origin = v->get_volume_offset();
     }
 
+#if ENABLE_ALLOW_NEGATIVE_Z
+    // Fixes flying instances
+#else
     // Fixes sinking/flying instances
+#endif // ENABLE_ALLOW_NEGATIVE_Z
     for (const std::pair<int, int>& i : done) {
         ModelObject* m = m_model->objects[i.first];
+#if ENABLE_ALLOW_NEGATIVE_Z
+        double shift_z = m->get_instance_min_z(i.second);
+        if (shift_z > 0.0) {
+            Vec3d shift(0.0, 0.0, -shift_z);
+#else
         Vec3d shift(0.0, 0.0, -m->get_instance_min_z(i.second));
+#endif // ENABLE_ALLOW_NEGATIVE_Z
         m_selection.translate(i.first, i.second, shift);
         m->translate_instance(i.second, shift);
+#if ENABLE_ALLOW_NEGATIVE_Z
+        }
+#endif // ENABLE_ALLOW_NEGATIVE_Z
     }
 
     if (object_moved)