diff --git a/addons/purchase/__terp__.py b/addons/purchase/__terp__.py
index c114a22ddb2..11d591340f8 100644
--- a/addons/purchase/__terp__.py
+++ b/addons/purchase/__terp__.py
@@ -5,12 +5,11 @@
 	"website" : "http://tinyerp.com/module_purchase.html",
 	"depends" : ["base", "account", "stock"],
 	"category" : "Generic Modules/Sales & Purchases",
-	"init_xml" : [],
+	"init_xml" : ["purchase_security.xml"],
 	"demo_xml" : ["purchase_demo.xml", 
 				  #"purchase_unit_test.xml"
 				  ],
 	"update_xml" : [
-		"purchase_security.xml",
 		"purchase_workflow.xml", 
 		"purchase_sequence.xml", 
 		"purchase_data.xml", 
diff --git a/addons/purchase/purchase_security.xml b/addons/purchase/purchase_security.xml
index 17758574c1c..2436b3159a2 100644
--- a/addons/purchase/purchase_security.xml
+++ b/addons/purchase/purchase_security.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0"?>
 <terp>
-	<data>
+	<data noupdate="1">
 
 		<record model="res.groups" id="group_purchase_manager">
 			<field name="name">Purchase Manager</field>