diff --git a/core/embed/upymod/modtrezorio/modtrezorio-hid.h b/core/embed/upymod/modtrezorio/modtrezorio-hid.h
index 9b6e7c0a37..ee92df81c1 100644
--- a/core/embed/upymod/modtrezorio/modtrezorio-hid.h
+++ b/core/embed/upymod/modtrezorio/modtrezorio-hid.h
@@ -150,18 +150,20 @@ STATIC mp_obj_t mod_trezorio_HID_read(size_t n_args, const mp_obj_t *args) {
   mp_buffer_info_t buf = {0};
   mp_get_buffer_raise(args[1], &buf, MP_BUFFER_WRITE);
 
-  int offset = mp_obj_get_int(args[2]);
+  int offset = 0;
+  if (n_args >= 2) {
+    offset = mp_obj_get_int(args[2]);
+  }
 
-  int len = buf.len - offset;
+  int limit;
   if (n_args >= 3) {
-    int limit = mp_obj_get_int(args[3]);
-    if ((limit - offset) < len) {
-      len = (limit - offset);
-    }
+    limit = mp_obj_get_int(args[3]);
+  } else {
+    limit = buf.len - offset;
   }
 
   ssize_t r =
-      usb_hid_read(o->info.iface_num, &((uint8_t *)buf.buf)[offset], len);
+      usb_hid_read(o->info.iface_num, &((uint8_t *)buf.buf)[offset], limit);
   return MP_OBJ_NEW_SMALL_INT(r);
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_trezorio_HID_read_obj, 3, 4,
diff --git a/core/embed/upymod/modtrezorio/modtrezorio-webusb.h b/core/embed/upymod/modtrezorio/modtrezorio-webusb.h
index bb3c639f14..20b69c99f8 100644
--- a/core/embed/upymod/modtrezorio/modtrezorio-webusb.h
+++ b/core/embed/upymod/modtrezorio/modtrezorio-webusb.h
@@ -136,21 +136,23 @@ STATIC mp_obj_t mod_trezorio_WebUSB_read(size_t n_args, const mp_obj_t *args) {
   mp_buffer_info_t buf = {0};
   mp_get_buffer_raise(args[1], &buf, MP_BUFFER_WRITE);
 
-  int offset = mp_obj_get_int(args[2]);
+  int offset = 0;
+  if (n_args >= 2) {
+    offset = mp_obj_get_int(args[2]);
+  }
 
-  int len = buf.len - offset;
+  int limit;
   if (n_args >= 3) {
-    int limit = mp_obj_get_int(args[3]);
-    if ((limit - offset) < len) {
-      len = (limit - offset);
-    }
+    limit = mp_obj_get_int(args[3]);
+  } else {
+    limit = buf.len - offset;
   }
 
   ssize_t r =
-      usb_webusb_read(o->info.iface_num, &((uint8_t *)buf.buf)[offset], len);
+      usb_webusb_read(o->info.iface_num, &((uint8_t *)buf.buf)[offset], limit);
   return MP_OBJ_NEW_SMALL_INT(r);
 }
-STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_trezorio_WebUSB_read_obj, 3, 4,
+STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_trezorio_WebUSB_read_obj, 2, 4,
                                            mod_trezorio_WebUSB_read);
 
 STATIC const mp_rom_map_elem_t mod_trezorio_WebUSB_locals_dict_table[] = {
diff --git a/core/tests/test_trezor.wire.codec.codec_v1.py b/core/tests/test_trezor.wire.codec.codec_v1.py
index 5a73467e25..b4551077aa 100644
--- a/core/tests/test_trezor.wire.codec.codec_v1.py
+++ b/core/tests/test_trezor.wire.codec.codec_v1.py
@@ -25,12 +25,23 @@ class MockHID:
         self.packet = packet
         return gen.send(len(packet))
 
-    def read(self, buffer):
+    def read(self, buffer, offset=0, limit=None):
         if self.packet is None:
             raise Exception("No packet to read")
-        buffer[:] = self.packet
-        self.packet = None
-        return len(buffer)
+        if limit is None:
+            limit = len(buffer) - offset
+
+        if len(self.packet) > limit:
+            end = offset + limit
+            buffer[offset:end] = self.packet[:limit]
+            self.packet = None
+            return limit
+        else:
+            end = offset + len(self.packet)
+            buffer[offset:end] = self.packet
+            read = len(self.packet)
+            self.packet = None
+            return read
 
     def wait_object(self, mode):
         return wait(mode | self.num)