diff --git a/src/osmo_gsm_tester/obj/ms_srs.py b/src/osmo_gsm_tester/obj/ms_srs.py
index aaeeca5..df83c2a 100644
--- a/src/osmo_gsm_tester/obj/ms_srs.py
+++ b/src/osmo_gsm_tester/obj/ms_srs.py
@@ -50,6 +50,7 @@
     config_schema = {
         'enable_pcap': schema.BOOL_STR,
         'log_all_level': schema.STR,
+        'log_nas_level': schema.STR
         }
     schema.register_config_schema('modem', config_schema)