diff --git a/esp8266/modnetwork.c b/esp8266/modnetwork.c
index 1d8a02b..762717b 100644
--- a/esp8266/modnetwork.c
+++ b/esp8266/modnetwork.c
@@ -97,7 +97,7 @@
 STATIC mp_obj_t esp_connect(mp_uint_t n_args, const mp_obj_t *args) {
     require_if(args[0], STATION_IF);
     struct station_config config = {{0}};
-    mp_uint_t len;
+    size_t len;
     const char *p;
 
     if (n_args > 1) {
@@ -311,7 +311,7 @@
                     }
                     case QS(MP_QSTR_essid): {
                         req_if = SOFTAP_IF;
-                        mp_uint_t len;
+                        size_t len;
                         const char *s = mp_obj_str_get_data(kwargs->table[i].value, &len);
                         len = MIN(len, sizeof(cfg.ap.ssid));
                         memcpy(cfg.ap.ssid, s, len);
@@ -330,7 +330,7 @@
                     }
                     case QS(MP_QSTR_password): {
                         req_if = SOFTAP_IF;
-                        mp_uint_t len;
+                        size_t len;
                         const char *s = mp_obj_str_get_data(kwargs->table[i].value, &len);
                         len = MIN(len, sizeof(cfg.ap.password) - 1);
                         memcpy(cfg.ap.password, s, len);