diff --git a/src/osmo_gsm_tester/bts_osmotrx.py b/src/osmo_gsm_tester/bts_osmotrx.py
index 731daa5..a964169 100644
--- a/src/osmo_gsm_tester/bts_osmotrx.py
+++ b/src/osmo_gsm_tester/bts_osmotrx.py
@@ -31,6 +31,7 @@
     trx = None
     pcu_sk_tmp_dir = None
     lac = None
+    cellid = None
 
     BIN_BTS_TRX = 'osmo-bts-trx'
     BIN_PCU = 'osmo-pcu'
@@ -139,6 +140,8 @@
         config.overlay(values, config.get_defaults('osmo_bts_trx'))
         if self.lac is not None:
             config.overlay(values, { 'location_area_code': self.lac })
+        if self.cellid is not None:
+            config.overlay(values, { 'cell_identity': self.cellid })
         config.overlay(values, self.conf)
         self.dbg(conf=values)
         return values
@@ -149,6 +152,9 @@
     def set_lac(self, lac):
         self.lac = lac
 
+    def set_cellid(self, cellid):
+        self.cellid = cellid
+
 class OsmoTrx(log.Origin):
     suite_run = None
     run_dir = None