diff --git a/cc3200/mods/modutime.c b/cc3200/mods/modutime.c
index 0aa853dd67..8e3c71402a 100644
--- a/cc3200/mods/modutime.c
+++ b/cc3200/mods/modutime.c
@@ -102,7 +102,7 @@ STATIC mp_obj_t time_localtime(mp_uint_t n_args, const mp_obj_t *args) {
 MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(time_localtime_obj, 0, 1, time_localtime);
 
 STATIC mp_obj_t time_mktime(mp_obj_t tuple) {
-    mp_uint_t len;
+    size_t len;
     mp_obj_t *elem;
 
     mp_obj_get_array(tuple, &len, &elem);
diff --git a/cc3200/mods/pybrtc.c b/cc3200/mods/pybrtc.c
index ddc26faf9c..13d7a49cba 100644
--- a/cc3200/mods/pybrtc.c
+++ b/cc3200/mods/pybrtc.c
@@ -196,7 +196,7 @@ STATIC uint pyb_rtc_datetime_s_us(const mp_obj_t datetime, uint32_t *seconds) {
 
     // set date and time
     mp_obj_t *items;
-    uint len;
+    size_t len;
     mp_obj_get_array(datetime, &len, &items);
 
     // verify the tuple
diff --git a/cc3200/mods/pybuart.c b/cc3200/mods/pybuart.c
index bab2b3d223..7fb51d83d1 100644
--- a/cc3200/mods/pybuart.c
+++ b/cc3200/mods/pybuart.c
@@ -388,7 +388,7 @@ STATIC mp_obj_t pyb_uart_init_helper(pyb_uart_obj_t *self, const mp_arg_val_t *a
     uint flowcontrol = UART_FLOWCONTROL_NONE;
     if (pins_o != mp_const_none) {
         mp_obj_t *pins;
-        mp_uint_t n_pins = 2;
+        size_t n_pins = 2;
         if (pins_o == MP_OBJ_NULL) {
             // use the default pins
             pins = (mp_obj_t *)pyb_uart_def_pin[self->uart_id];
@@ -454,7 +454,7 @@ STATIC mp_obj_t pyb_uart_make_new(const mp_obj_type_t *type, size_t n_args, size
     if (args[0].u_obj == MP_OBJ_NULL) {
         if (args[5].u_obj != MP_OBJ_NULL) {
             mp_obj_t *pins;
-            mp_uint_t n_pins = 2;
+            size_t n_pins = 2;
             mp_obj_get_array(args[5].u_obj, &n_pins, &pins);
             // check the Tx pin (or the Rx if Tx is None)
             if (pins[0] == mp_const_none) {