diff --git a/rudder-core/src/main/scala/com/normation/rudder/services/policies/nodeconfig/NodeConfigurationServiceImpl.scala b/rudder-core/src/main/scala/com/normation/rudder/services/policies/nodeconfig/NodeConfigurationServiceImpl.scala
index 59fd52b95fb..5cabc8802f8 100644
--- a/rudder-core/src/main/scala/com/normation/rudder/services/policies/nodeconfig/NodeConfigurationServiceImpl.scala
+++ b/rudder-core/src/main/scala/com/normation/rudder/services/policies/nodeconfig/NodeConfigurationServiceImpl.scala
@@ -90,9 +90,10 @@ class DetectChangeInNodeConfiguration extends Loggable {
     logger.trace(s"Checking changes in node '${targetConfig.nodeInfo.id.value}'")
     val changedRuleIds = currentOpt match {
       case None =>
-        //what do we do if we don't have a cache for the node ? All the target rules are "changes" ?
+        //what do we do if we don't have a cache for the node ? All the target rules are "changes" ? No, we skip,
+        // as all changes will be caught later. Otherwise, it will increase the serial of all rules applied to this node
         logger.trace("`-> No node configuration cache availabe for that node")
-        targetConfig.policyDrafts.map( _.ruleId ).toSet
+        Set[RuleId]()
       case Some(current) =>
 
         val target = NodeConfigurationCache(targetConfig)
@@ -128,8 +129,9 @@ class DetectChangeInNodeConfiguration extends Loggable {
               logger.trace(s"`-> rule with ID '${ruleId.value}' was deleted")
               Set(ruleId)
             case (None, Some(PolicyCache(ruleId, _, _))) =>
-              logger.trace(s"`-> rule with ID '${ruleId.value}' was added")
-              Set(ruleId)
+              logger.trace(s"`-> rule with ID '${ruleId.value}' was added, skipping it")
+              // Ignoring nodes addition to Rules. The node will be updated, thanks to the check on change of hash of node config
+              Set[RuleId]()
             case (Some(PolicyCache(r0, d0, c0)), Some(PolicyCache(r1, d1, c1))) =>
               //d0 and d1 are equals by construction, but keep them for future-proofing
               if(d0 == d1) {
diff --git a/rudder-core/src/test/scala/com/normation/rudder/services/nodes/NodeConfigurationChangeDetectServiceTest.scala b/rudder-core/src/test/scala/com/normation/rudder/services/nodes/NodeConfigurationChangeDetectServiceTest.scala
index 65706f18942..cc4232d9e35 100644
--- a/rudder-core/src/test/scala/com/normation/rudder/services/nodes/NodeConfigurationChangeDetectServiceTest.scala
+++ b/rudder-core/src/test/scala/com/normation/rudder/services/nodes/NodeConfigurationChangeDetectServiceTest.scala
@@ -247,12 +247,12 @@ class NodeConfigurationChangeDetectServiceTest extends Specification {
       ) === Set(new RuleId("ruleId1"))
     }
 
-    "have a change if nothing is different, but previous CR is not existant" in {
+    "have no change if nothing is different, but previous CR is not existant (extending a Rule should be free)" in {
       service.detectChangeInNode(
           Some(NodeConfigurationCache(emptyNodeConfig))
         , complexeNodeConfig
         , directiveLib
-      ) === Set(new RuleId("ruleId1"))
+      )  must beTheSameAs(Set())
     }
 
     "have a change if nothing is different, but previous CR is existant and current is non existant" in {