diff --git a/core/src/apps/common/cbor.py b/core/src/apps/common/cbor.py
index 4edbfac9c..f37681d71 100644
--- a/core/src/apps/common/cbor.py
+++ b/core/src/apps/common/cbor.py
@@ -139,7 +139,7 @@ def _cbor_decode(cbor):
         return (data[0:ln], data[ln:])
     elif fb_type == _CBOR_TEXT_STRING:
         ln, data = _read_length(cbor[1:], fb_aux)
-        return (data[0:ln].decode(), data[ln:])
+        return (bytes(data[0:ln]).decode(), data[ln:])
     elif fb_type == _CBOR_ARRAY:
         if fb_aux == _CBOR_VAR_FOLLOWS:
             res = []