diff --git a/src/py/flwr/cli/ls.py b/src/py/flwr/cli/ls.py
index f1c6a242cd33..45956bae0dc2 100644
--- a/src/py/flwr/cli/ls.py
+++ b/src/py/flwr/cli/ls.py
@@ -305,7 +305,7 @@ def _to_json(run_list: list[_RunListType]) -> str:
             }
         )
 
-    return json.dumps({"runs": runs_list})
+    return json.dumps({"success": True, "runs": runs_list})
 
 
 def _list_runs(