diff --git a/pySim/tlv.py b/pySim/tlv.py
index 1ecc8066..c85d92b6 100644
--- a/pySim/tlv.py
+++ b/pySim/tlv.py
@@ -87,7 +87,7 @@ class Transcodable(abc.ABC):
     def to_bytes(self) -> bytes:
         """Convert from internal representation to binary bytes.  Store the binary result
         in the internal state and return it."""
-        if not self.decoded:
+        if self.decoded == None:
             do = b''
         elif self._construct:
             do = self._construct.build(self.decoded, total_len=None)