diff --git a/micropython/extmod/modtrezorcrypto/modtrezorcrypto-bip32.h b/micropython/extmod/modtrezorcrypto/modtrezorcrypto-bip32.h
index f75074fe..7ff6d983 100644
--- a/micropython/extmod/modtrezorcrypto/modtrezorcrypto-bip32.h
+++ b/micropython/extmod/modtrezorcrypto/modtrezorcrypto-bip32.h
@@ -47,7 +47,7 @@ STATIC mp_obj_t mod_TrezorCrypto_HDNode_derive_path(mp_obj_t self, mp_obj_t path
     mp_obj_HDNode_t *o = MP_OBJ_TO_PTR(self);
 
     // get path objects and length
-    mp_uint_t plen;
+    size_t plen;
     mp_obj_t *pitems;
     mp_obj_get_array(path, &plen, &pitems);
     if (plen > 32) {
diff --git a/micropython/extmod/modtrezorcrypto/modtrezorcrypto-ed25519.h b/micropython/extmod/modtrezorcrypto/modtrezorcrypto-ed25519.h
index 5df146a0..dd2da324 100644
--- a/micropython/extmod/modtrezorcrypto/modtrezorcrypto-ed25519.h
+++ b/micropython/extmod/modtrezorcrypto/modtrezorcrypto-ed25519.h
@@ -106,7 +106,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_TrezorCrypto_Ed25519_verify_obj,
 ///     Combines a list of public keys used in COSI cosigning scheme
 ///     '''
 STATIC mp_obj_t mod_TrezorCrypto_Ed25519_cosi_combine_publickeys(mp_obj_t self, mp_obj_t public_keys) {
-    mp_uint_t pklen;
+    size_t pklen;
     mp_obj_t *pkitems;
     mp_obj_get_array(public_keys, &pklen, &pkitems);
     if (pklen > 15) {
@@ -140,7 +140,7 @@ STATIC mp_obj_t mod_TrezorCrypto_Ed25519_cosi_combine_signatures(mp_obj_t self,
     if (sigR.len != 32) {
         mp_raise_ValueError("Invalid length of R");
     }
-    mp_uint_t siglen;
+    size_t siglen;
     mp_obj_t *sigitems;
     mp_obj_get_array(signatures, &siglen, &sigitems);
     if (siglen > 15) {
diff --git a/micropython/extmod/modtrezorcrypto/modtrezorcrypto-random.h b/micropython/extmod/modtrezorcrypto/modtrezorcrypto-random.h
index dc5bbc45..743eac59 100644
--- a/micropython/extmod/modtrezorcrypto/modtrezorcrypto-random.h
+++ b/micropython/extmod/modtrezorcrypto/modtrezorcrypto-random.h
@@ -54,7 +54,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_2(mod_TrezorCrypto_Random_bytes_obj, mod_TrezorCr
 ///     Shuffles items of given list (in-place)
 ///     '''
 STATIC mp_obj_t mod_TrezorCrypto_Random_shuffle(mp_obj_t self, mp_obj_t data) {
-    mp_uint_t item_cnt;
+    size_t item_cnt;
     mp_obj_t *items;
     mp_obj_get_array(data, &item_cnt, &items);
     if (item_cnt > 256) {
diff --git a/micropython/extmod/modtrezorcrypto/modtrezorcrypto-ssss.h b/micropython/extmod/modtrezorcrypto/modtrezorcrypto-ssss.h
index 5d38ee0b..091edcb8 100644
--- a/micropython/extmod/modtrezorcrypto/modtrezorcrypto-ssss.h
+++ b/micropython/extmod/modtrezorcrypto/modtrezorcrypto-ssss.h
@@ -58,14 +58,14 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_TrezorCrypto_SSSS_split_obj, 4, 4
 ///     Combine M shares of Shamir's Secret Sharing Scheme into secret
 ///     '''
 STATIC mp_obj_t mod_TrezorCrypto_SSSS_combine(mp_obj_t self, mp_obj_t shares) {
-    mp_uint_t n;
+    size_t n;
     mp_obj_t *share;
     mp_obj_get_array(shares, &n, &share);
     if (n < 1 || n > 15) {
         mp_raise_ValueError("Invalid number of shares");
     }
     bignum256 bnshares[n];
-    for (mp_uint_t i = 0; i < n; i++) {
+    for (size_t i = 0; i < n; i++) {
         if (MP_OBJ_IS_TYPE(share[i], &mp_type_bytes)) {
             mp_buffer_info_t s;
             mp_get_buffer_raise(share[i], &s, MP_BUFFER_READ);
diff --git a/micropython/extmod/modtrezormsg/modtrezormsg.c b/micropython/extmod/modtrezormsg/modtrezormsg.c
index 89952da9..b5242f78 100644
--- a/micropython/extmod/modtrezormsg/modtrezormsg.c
+++ b/micropython/extmod/modtrezormsg/modtrezormsg.c
@@ -45,14 +45,14 @@ STATIC mp_obj_t mod_TrezorMsg_Msg_make_new(const mp_obj_type_t *type, size_t n_a
 ///     Configures USB interfaces with a list/tuple of (usage_page, ...)
 ///     '''
 STATIC mp_obj_t mod_TrezorMsg_Msg_set_interfaces(mp_obj_t self, mp_obj_t ifaces) {
-    mp_uint_t iface_cnt;
+    size_t iface_cnt;
     mp_obj_t *usage_pages;
     mp_obj_get_array(ifaces, &iface_cnt, &usage_pages);
     if (iface_cnt > MAX_INTERFACES) {
         mp_raise_ValueError("Maximum number of interfaces exceeded");
     }
     mp_obj_Msg_t *o = MP_OBJ_TO_PTR(self);
-    for (mp_uint_t i = 0; i < iface_cnt; i++) {
+    for (size_t i = 0; i < iface_cnt; i++) {
        uint16_t usage_page = mp_obj_get_int(usage_pages[i]);
        o->usage_pages[i] = usage_page;
     }
diff --git a/micropython/extmod/modtrezorui/modtrezorui-display.h b/micropython/extmod/modtrezorui/modtrezorui-display.h
index 61695043..169f5531 100644
--- a/micropython/extmod/modtrezorui/modtrezorui-display.h
+++ b/micropython/extmod/modtrezorui/modtrezorui-display.h
@@ -331,7 +331,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_TrezorUi_Display_backlight_obj, 1
 STATIC mp_obj_t mod_TrezorUi_Display_offset(size_t n_args, const mp_obj_t *args) {
     int xy[2], *ret;
     if (n_args > 1) {
-        mp_uint_t xy_cnt;
+        size_t xy_cnt;
         mp_obj_t *xy_obj;
         if (MP_OBJ_IS_TYPE(args[1], &mp_type_tuple)) {
             mp_obj_tuple_get(args[1], &xy_cnt, &xy_obj);