diff --git a/src/edt/edt/edtPCellParametersPage.cc b/src/edt/edt/edtPCellParametersPage.cc
index 8f27d312b..a2153d22a 100644
--- a/src/edt/edt/edtPCellParametersPage.cc
+++ b/src/edt/edt/edtPCellParametersPage.cc
@@ -387,6 +387,7 @@ PCellParametersPage::setup (lay::LayoutViewBase *view, int cv_index, const db::P
     delete mp_parameters_area;
   }
 
+  mp_groups.clear ();
   m_widgets.clear ();
   m_icon_widgets.clear ();
   m_all_widgets.clear ();