diff --git a/openbsc/include/openbsc/abis_rsl.h b/openbsc/include/openbsc/abis_rsl.h
index a911be3..b76d0fa 100644
--- a/openbsc/include/openbsc/abis_rsl.h
+++ b/openbsc/include/openbsc/abis_rsl.h
@@ -547,7 +547,7 @@
 			      int n_pag_blocks);
 unsigned int n_pag_blocks(int bs_ccch_sdcch_comb, unsigned int bs_ag_blks_res);
 u_int64_t str_to_imsi(const char *imsi_str);
-u_int8_t lchan2chan_nr(struct gsm_lchan *lchan);
+u_int8_t lchan2chan_nr(const struct gsm_lchan *lchan);
 int rsl_release_request(struct gsm_lchan *lchan, u_int8_t link_id);
 
 /* to be provided by external code */
diff --git a/openbsc/src/abis_rsl.c b/openbsc/src/abis_rsl.c
index 8a4ed9b..d5c883e 100644
--- a/openbsc/src/abis_rsl.c
+++ b/openbsc/src/abis_rsl.c
@@ -241,7 +241,7 @@
 }
 
 /* See Table 10.5.25 of GSM04.08 */
-u_int8_t lchan2chan_nr(struct gsm_lchan *lchan)
+u_int8_t lchan2chan_nr(const struct gsm_lchan *lchan)
 {
 	struct gsm_bts_trx_ts *ts = lchan->ts;
 	u_int8_t cbits, chan_nr;
diff --git a/openbsc/src/db.c b/openbsc/src/db.c
index 369505a..5dfefb5 100644
--- a/openbsc/src/db.c
+++ b/openbsc/src/db.c
@@ -265,7 +265,7 @@
 {
 	dbi_result result;
 	const char *string;
-	unsigned int cm1;
+	unsigned char cm1;
 	const unsigned char *cm2, *cm3;
 	struct gsm_equipment *equip = &subscr->equipment;