diff --git a/sessions/sessions.go b/sessions/sessions.go
index 460c5c7bb..5f05e9374 100644
--- a/sessions/sessions.go
+++ b/sessions/sessions.go
@@ -2550,9 +2550,6 @@ func (sS *SessionS) BiRPCv1ProcessCDR(clnt rpcclient.RpcClientConnection,
 	if cgrEvWithArgDisp.ID == "" {
 		cgrEvWithArgDisp.ID = utils.GenUUID()
 	}
-	if _, has := cgrEvWithArgDisp.Event[utils.Source]; !has {
-		cgrEvWithArgDisp.Event[utils.Source] = utils.MetaSessionS
-	}
 
 	// RPC caching
 	if sS.cgrCfg.CacheCfg()[utils.CacheRPCResponses].Limit != 0 {
@@ -2573,6 +2570,10 @@ func (sS *SessionS) BiRPCv1ProcessCDR(clnt rpcclient.RpcClientConnection,
 			nil, true, utils.NonTransactional)
 	}
 	// end of RPC caching
+	// in case that source don't exist add it
+	if _, has := cgrEvWithArgDisp.Event[utils.Source]; !has {
+		cgrEvWithArgDisp.Event[utils.Source] = utils.MetaSessionS
+	}
 
 	ev := engine.NewSafEvent(cgrEvWithArgDisp.Event)
 	cgrID := GetSetCGRID(ev)