diff --git a/src/call-barring.c b/src/call-barring.c
index d2143b23..2ed0a743 100644
--- a/src/call-barring.c
+++ b/src/call-barring.c
@@ -342,7 +342,7 @@ static void cb_ss_set_lock_callback(const struct ofono_error *error,
 }
 
 static gboolean cb_ss_control(struct ofono_modem *modem,
-				int type, const char *sc,
+				enum ss_control_type type, const char *sc,
 				const char *sia, const char *sib,
 				const char *sic, const char *dn,
 				DBusMessage *msg)
diff --git a/src/call-forwarding.c b/src/call-forwarding.c
index 9cb378c7..d7316bc5 100644
--- a/src/call-forwarding.c
+++ b/src/call-forwarding.c
@@ -917,7 +917,8 @@ static void cf_ss_control_callback(const struct ofono_error *error, void *data)
 	ss_set_query_next_cf_cond(modem);
 }
 
-static gboolean cf_ss_control(struct ofono_modem *modem, int type, const char *sc,
+static gboolean cf_ss_control(struct ofono_modem *modem,
+				enum ss_control_type type, const char *sc,
 				const char *sia, const char *sib,
 				const char *sic, const char *dn,
 				DBusMessage *msg)
diff --git a/src/call-settings.c b/src/call-settings.c
index 23222260..364220d1 100644
--- a/src/call-settings.c
+++ b/src/call-settings.c
@@ -377,7 +377,8 @@ static void cw_ss_set_callback(const struct ofono_error *error, void *data)
 				cw_ss_query_callback, modem);
 }
 
-static gboolean cw_ss_control(struct ofono_modem *modem, int type,
+static gboolean cw_ss_control(struct ofono_modem *modem,
+				enum ss_control_type type,
 				const char *sc, const char *sia,
 				const char *sib, const char *sic,
 				const char *dn, DBusMessage *msg)
@@ -540,7 +541,8 @@ static void clip_colp_colr_ss_query_cb(const struct ofono_error *error,
 	generate_ss_query_reply(modem, context, value);
 }
 
-static gboolean clip_colp_colr_ss(struct ofono_modem *modem, int type,
+static gboolean clip_colp_colr_ss(struct ofono_modem *modem,
+				enum ss_control_type type,
 				const char *sc, const char *sia,
 				const char *sib, const char *sic,
 				const char *dn, DBusMessage *msg)
@@ -663,7 +665,8 @@ static void clir_ss_set_callback(const struct ofono_error *error, void *data)
 	cs->ops->clir_query(modem, clir_ss_query_callback, modem);
 }
 
-static gboolean clir_ss_control(struct ofono_modem *modem, int type,
+static gboolean clir_ss_control(struct ofono_modem *modem,
+				enum ss_control_type type,
 				const char *sc, const char *sia,
 				const char *sib, const char *sic,
 				const char *dn, DBusMessage *msg)
diff --git a/src/ussd.h b/src/ussd.h
index 7d8c6d9d..bfd707f3 100644
--- a/src/ussd.h
+++ b/src/ussd.h
@@ -26,7 +26,8 @@ struct ussd_data {
 	int flags;
 };
 
-typedef gboolean (*ss_control_cb_t)(struct ofono_modem *modem, int type,
+typedef gboolean (*ss_control_cb_t)(struct ofono_modem *modem,
+					enum ss_control_type type,
 					const char *sc,
 					const char *sia, const char *sib,
 					const char *sic, const char *dn,