diff --git a/targets/RT/USER/lte-ru.c b/targets/RT/USER/lte-ru.c
index 8cdf3f6949..a46f5858ac 100644
--- a/targets/RT/USER/lte-ru.c
+++ b/targets/RT/USER/lte-ru.c
@@ -2200,6 +2200,7 @@ void init_RU(char *rf_config_file) {
     ru->idx          = ru_id;              
     ru->ts_offset    = 0;
     ru->is_slave     = (ru_id == 0) ? 0 : 1;
+    ru->in_synch     = (ru->is_slave == 1) ? 0 : 1;
     // use eNB_list[0] as a reference for RU frame parameters
     // NOTE: multiple CC_id are not handled here yet!