diff --git a/src/slic3r/GUI/GLCanvas3D.hpp b/src/slic3r/GUI/GLCanvas3D.hpp
index 990bf4782..1dde132c8 100644
--- a/src/slic3r/GUI/GLCanvas3D.hpp
+++ b/src/slic3r/GUI/GLCanvas3D.hpp
@@ -566,6 +566,7 @@ public:
     float get_view_toolbar_height() const { return m_view_toolbar.get_height(); }
 
     int get_move_volume_id() const { return m_mouse.drag.move_volume_idx; }
+    int get_hover_volume_id() const { return m_hover_volume_id; }
 
     // Returns the view ray line, in world coordinate, at the given mouse position.
     Linef3 mouse_ray(const Point& mouse_pos);
diff --git a/src/slic3r/GUI/Gizmos/GLGizmosManager.cpp b/src/slic3r/GUI/Gizmos/GLGizmosManager.cpp
index 9e2386f90..35bf2ef8a 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmosManager.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmosManager.cpp
@@ -663,6 +663,11 @@ bool GLGizmosManager::on_mouse(wxMouseEvent& evt, GLCanvas3D& canvas)
             gizmo_event(SLAGizmoEventType::LeftUp, mouse_pos, evt.ShiftDown());
             processed = true;
         }
+        else if (evt.LeftUp() && (m_current == Flatten) && ((canvas.get_hover_volume_id() != -1) || grabber_contains_mouse()))
+        {
+            // to avoid to loose the selection when user clicks an object while the Flatten gizmo is active
+            processed = true;
+        }
     }
     else
     {