diff --git a/patches/february_2013/p03_material_request.py b/patches/february_2013/p03_material_request.py
index 612c108..1a9a433 100644
--- a/patches/february_2013/p03_material_request.py
+++ b/patches/february_2013/p03_material_request.py
@@ -3,8 +3,11 @@
 def execute():
 	webnotes.reload_doc("core", "doctype", "doctype")
 	
-	webnotes.rename_doc("DocType", "Purchase Request Item", "Material Request Item", force=True)
-	webnotes.rename_doc("DocType", "Purchase Request", "Material Request", force=True)
+	tables = webnotes.conn.sql_list("sthow tables")
+	if not "Material Request Item" in tables:
+		webnotes.rename_doc("DocType", "Purchase Request Item", "Material Request Item", force=True)
+	if not "Material Request" in tables:
+		webnotes.rename_doc("DocType", "Purchase Request", "Material Request", force=True)
 	webnotes.reload_doc("buying", "search_criteria", "pending_po_items_to_bill")
 	webnotes.reload_doc("buying", "search_criteria", "pending_po_items_to_receive")