diff --git a/openbsc/src/abis_nm.c b/openbsc/src/abis_nm.c
index e7e3bf0..fc00ca8 100644
--- a/openbsc/src/abis_nm.c
+++ b/openbsc/src/abis_nm.c
@@ -635,7 +635,7 @@
 		nm_state = &trx->bb_transc.nm_state;
 		break;
 	case NM_OC_CHANNEL:
-		if (obj_inst->trx_nr > bts->num_trx) {
+		if (obj_inst->trx_nr >= bts->num_trx) {
 			DEBUGPC(DNM, "TRX %u does not exist ", obj_inst->trx_nr);
 			return NULL;
 		}
@@ -719,7 +719,7 @@
 		obj = &trx->bb_transc;
 		break;
 	case NM_OC_CHANNEL:
-		if (obj_inst->trx_nr > bts->num_trx) {
+		if (obj_inst->trx_nr >= bts->num_trx) {
 			DEBUGPC(DNM, "TRX %u does not exist ", obj_inst->trx_nr);
 			return NULL;
 		}