diff --git a/docker/CMSRucioClient/loadtest/loadtest.py b/docker/CMSRucioClient/loadtest/loadtest.py
index e75ca2c9..e671b08d 100755
--- a/docker/CMSRucioClient/loadtest/loadtest.py
+++ b/docker/CMSRucioClient/loadtest/loadtest.py
@@ -315,40 +315,39 @@ def run(source_rse_expression, dest_rse_expression, account, activity, filesize)
                     client, uploader, source_rse, filesize, next_filenumber
                 )
                 if not success:
-                    logger.error(
-                        f"RSE {source_rse} has no source files and could not upload, skipping"
-                    )
+                    logger.error(f"RSE {source_rse} has no source files and could not upload, skipping")
                     continue
                 source_files = list(client.list_files("cms", dataset))
 
-            dest_rules = client.list_replication_rules(
-                {
-                    "scope": "cms",
-                    "name": dataset,
-                    "account": account,
-                    "activity": activity,
-                }
-            )
-            dest_rules = {
-                rule["rse_expression"]: rule
-                for rule in dest_rules
-                if rule["source_replica_expression"] == source_rse
+            dest_rules = { rule["rse_expression"]: rule
+                for rule in client.list_did_rules("cms", dataset)
             }
-
             for dest_rse in dest_rses:
-                if dest_rse == source_rse:
-                    continue
                 dest_rule = dest_rules.get(dest_rse, None)
-                update_loadtest(
-                    client,
-                    source_rse,
-                    dest_rse,
-                    source_files,
-                    dest_rule,
-                    dataset,
-                    account,
-                    activity,
-                )
+                if dest_rse == source_rse:
+                    if dest_rule is None:
+                        logger.info(f"Adding new replication rule at src for rse {source_rse}")
+                        client.add_replication_rule (
+                            dids = [{"scope": "cms", "name": dataset}],
+                            copies = 1,
+                            rse_expression = source_rse,
+                            account = account,
+                            activity = "Functional Test",
+                            ignore_availability = True,
+                            comment = "Locking loadtest replicas at source"
+                        )
+                
+                else:
+                    update_loadtest(
+                        client,
+                        source_rse,
+                        dest_rse,
+                        source_files,
+                        dest_rule,
+                        dataset,
+                        account,
+                        activity,
+                    )
 
         cycle_time = (datetime.datetime.utcnow() - cycle_start).total_seconds()
         logger.info(f"Completed loadtest cycle in {cycle_time}s")