diff --git a/src/osmo_gsm_tester/obj/enb.py b/src/osmo_gsm_tester/obj/enb.py
index 6384f15..fea78de 100644
--- a/src/osmo_gsm_tester/obj/enb.py
+++ b/src/osmo_gsm_tester/obj/enb.py
@@ -34,6 +34,7 @@
         'rx_gain': schema.UINT,
         'rf_dev_type': schema.STR,
         'rf_dev_args': schema.STR,
+        'rf_dev_sync': schema.STR,
         'additional_args[]': schema.STR,
         'inactivity_timer': schema.INT,
         'enable_measurements': schema.BOOL_STR,
diff --git a/src/osmo_gsm_tester/obj/enb_amarisoft.py b/src/osmo_gsm_tester/obj/enb_amarisoft.py
index 0f8944f..1fc4485 100644
--- a/src/osmo_gsm_tester/obj/enb_amarisoft.py
+++ b/src/osmo_gsm_tester/obj/enb_amarisoft.py
@@ -214,6 +214,7 @@
         # different cfg namespace 'trx'. Copy needed values over there:
         config.overlay(values, dict(trx=dict(rf_dev_type=values['enb'].get('rf_dev_type', None),
                                              rf_dev_args=values['enb'].get('rf_dev_args', None),
+                                             rf_dev_sync=values['enb'].get('rf_dev_sync', None),
                                              rx_gain=values['enb'].get('rx_gain', None),
                                              tx_gain=values['enb'].get('tx_gain', None),
                                             )))
diff --git a/src/osmo_gsm_tester/templates/amarisoft_rf_driver.cfg.tmpl b/src/osmo_gsm_tester/templates/amarisoft_rf_driver.cfg.tmpl
index cd08835..05689c7 100644
--- a/src/osmo_gsm_tester/templates/amarisoft_rf_driver.cfg.tmpl
+++ b/src/osmo_gsm_tester/templates/amarisoft_rf_driver.cfg.tmpl
@@ -1,8 +1,7 @@
 rf_driver: {
     name: "${trx.rf_dev_type}",
-    sync: "${'1' if trx.rf_dev_type == 'zmq' else 'none'}",
-
     args: "${trx.rf_dev_args}",
+    sync: "${trx.rf_dev_sync}",
 
 % if trx.rf_dev_type == 'zmq':
     dl_sample_bits: 16,
diff --git a/sysmocom/defaults.conf b/sysmocom/defaults.conf
index b175cbb..ed0b575 100644
--- a/sysmocom/defaults.conf
+++ b/sysmocom/defaults.conf
@@ -154,6 +154,7 @@
   enable_pcap: false
   tx_gain: 89
   rx_gain: 60
+  rf_dev_sync: none
   log_options: all.level=error,all.max_size=0,nas.level=debug,nas.max_size=1,s1ap.level=debug,s1ap.max_size=1,x2ap.level=debug,x2ap.max_size=1,rrc.level=debug,rrc.max_size=1
 
 srsue: