diff --git a/src/share/system_variable/ob_system_variable.cpp b/src/share/system_variable/ob_system_variable.cpp
index 48582e01cfd41498f657846f74c0e9c42d9dc219..02c9c5cabd0bb75c9b2a76e11e0034f1ba3d7b20 100644
--- a/src/share/system_variable/ob_system_variable.cpp
+++ b/src/share/system_variable/ob_system_variable.cpp
@@ -1560,6 +1560,7 @@ int ObSysVarOnCheckFuncs::check_and_convert_timestamp_service(
               set_var.var_name_.ptr(),
               in_str.length(),
               in_str.ptr());
+          LOG_WARN("only 'LTS' is supported under sys tenant");
         }
       }
     } else {