diff --git a/src/osmo-bsc/abis_om2000.c b/src/osmo-bsc/abis_om2000.c
index a1a6c2195..95316115b 100644
--- a/src/osmo-bsc/abis_om2000.c
+++ b/src/osmo-bsc/abis_om2000.c
@@ -932,7 +932,7 @@ static struct gsm_nm_state *mo2nm_state(struct gsm_bts *bts, const struct abis_o
 	return nm_state;
 }
 
-static void *mo2obj(struct gsm_bts *bts, struct abis_om2k_mo *mo)
+static void *mo2obj(struct gsm_bts *bts, const struct abis_om2k_mo *mo)
 {
 	struct gsm_bts_trx *trx;