diff --git a/server/AyaNova/biz/PartAssemblyBiz.cs b/server/AyaNova/biz/PartAssemblyBiz.cs
index 27f124ed..e658541d 100644
--- a/server/AyaNova/biz/PartAssemblyBiz.cs
+++ b/server/AyaNova/biz/PartAssemblyBiz.cs
@@ -463,6 +463,7 @@ namespace AyaNova.Biz
                         ImportUtil.Update(Source, Target, propertiesToUpdate);
                         if (j["Items"] != null)
                         {
+                            Target.Items.Clear();
                             foreach (PartAssemblyItem ipi in ImportPartAssemblyItems)
                                 Target.Items.Add(ipi);
                         }