diff --git a/openbsc/src/libcommon/gsm_data_shared.c b/openbsc/src/libcommon/gsm_data_shared.c
index 4eea21e..b8853ad 100644
--- a/openbsc/src/libcommon/gsm_data_shared.c
+++ b/openbsc/src/libcommon/gsm_data_shared.c
@@ -328,8 +328,11 @@
 
 char *gsm_trx_name(const struct gsm_bts_trx *trx)
 {
-	snprintf(ts2str, sizeof(ts2str), "(bts=%d,trx=%d)",
-		 trx->bts->nr, trx->nr);
+	if (!trx)
+		snprintf(ts2str, sizeof(ts2str), "(trx=NULL)");
+	else
+		snprintf(ts2str, sizeof(ts2str), "(bts=%d,trx=%d)",
+			 trx->bts->nr, trx->nr);
 
 	return ts2str;
 }