diff --git a/drivers/atmodem/sim.c b/drivers/atmodem/sim.c
index 1c668b17..b7d83684 100644
--- a/drivers/atmodem/sim.c
+++ b/drivers/atmodem/sim.c
@@ -565,21 +565,21 @@ static const char *const at_clck_cpwd_fac[] = {
 	[OFONO_SIM_PASSWORD_PHCORP_PIN] = "PC",
 };
 
-static void at_pin_enable(struct ofono_sim *sim, int passwd_type, int enable,
-			const char *passwd,
-			ofono_sim_lock_unlock_cb_t cb, void *data)
+static void at_pin_enable(struct ofono_sim *sim,
+				enum ofono_sim_password_type passwd_type,
+				int enable, const char *passwd,
+				ofono_sim_lock_unlock_cb_t cb, void *data)
 {
 	GAtChat *chat = ofono_sim_get_data(sim);
 	struct cb_data *cbd = cb_data_new(cb, data);
 	char buf[64];
 	int ret;
-	int len = sizeof(at_clck_cpwd_fac) / sizeof(*at_clck_cpwd_fac);
+	unsigned int len = sizeof(at_clck_cpwd_fac) / sizeof(*at_clck_cpwd_fac);
 
 	if (!cbd)
 		goto error;
 
-	if (passwd_type < 0 || passwd_type >= len ||
-			!at_clck_cpwd_fac[passwd_type])
+	if (passwd_type >= len || !at_clck_cpwd_fac[passwd_type])
 		goto error;
 
 	snprintf(buf, sizeof(buf), "AT+CLCK=\"%s\",%i,\"%s\"",
diff --git a/include/sim.h b/include/sim.h
index 3d618270..af2fd1eb 100644
--- a/include/sim.h
+++ b/include/sim.h
@@ -85,7 +85,8 @@ typedef void (*ofono_sim_file_read_cb_t)(int ok,
 typedef void (*ofono_sim_file_write_cb_t)(int ok, void *userdata);
 
 typedef void (*ofono_sim_passwd_cb_t)(const struct ofono_error *error,
-					int passwd_type, void *data);
+					enum ofono_sim_password_type type,
+					void *data);
 
 typedef void (*ofono_sim_lock_unlock_cb_t)(const struct ofono_error *error,
 					void *data);
@@ -127,8 +128,8 @@ struct ofono_sim_driver {
 			enum ofono_sim_password_type type,
 			const char *old, const char *new,
 			ofono_sim_lock_unlock_cb_t cb, void *data);
-	void (*lock)(struct ofono_sim *sim, int passwd_type, int enable,
-			const char *passwd,
+	void (*lock)(struct ofono_sim *sim, enum ofono_sim_password_type type,
+			int enable, const char *passwd,
 			ofono_sim_lock_unlock_cb_t cb, void *data);
 };
 
diff --git a/src/sim.c b/src/sim.c
index 7338fe7b..8f244597 100644
--- a/src/sim.c
+++ b/src/sim.c
@@ -78,7 +78,7 @@ struct ofono_sim {
 	GSList *service_numbers;
 	gboolean sdn_ready;
 	gboolean ready;
-	int pin_type;
+	enum ofono_sim_password_type pin_type;
 	char **language_prefs;
 	GQueue *simop_q;
 	gint simop_source;
@@ -569,7 +569,7 @@ static DBusMessage *sim_enter_pin(DBusConnection *conn, DBusMessage *msg,
 	struct ofono_sim *sim = data;
 	DBusMessageIter iter;
 	const char *typestr;
-	int type;
+	enum ofono_sim_password_type type;
 	const char *pin;
 
 	if (!sim->driver->send_passwd)
@@ -611,7 +611,7 @@ static DBusMessage *sim_reset_pin(DBusConnection *conn, DBusMessage *msg,
 	struct ofono_sim *sim = data;
 	DBusMessageIter iter;
 	const char *typestr;
-	int type;
+	enum ofono_sim_password_type type;
 	const char *puk;
 	const char *pin;
 
@@ -926,7 +926,8 @@ static void sim_retrieve_imsi(struct ofono_sim *sim)
 	sim->driver->read_imsi(sim, sim_imsi_cb, sim);
 }
 
-static void sim_pin_query_cb(const struct ofono_error *error, int pin_type,
+static void sim_pin_query_cb(const struct ofono_error *error,
+				enum ofono_sim_password_type pin_type,
 				void *data)
 {
 	struct ofono_sim *sim = data;