diff --git a/qt/update_dialog.cpp b/qt/update_dialog.cpp
index f5b21af45b..c68848ecf6 100644
--- a/qt/update_dialog.cpp
+++ b/qt/update_dialog.cpp
@@ -277,6 +277,10 @@ namespace qt
           LOG(LWARNING, ("Duplicate CountryId in results for query:", query));
       }
 
+      // Clear the tree to avoid creating duplicate nodes for countries
+      // that appear in more than one onResults call.
+      m_tree->clear();
+      m_treeItemByCountryId.clear();
       FillTree(filter, timestamp);
     };