diff --git a/tests/tivars.py b/tests/tivars.py
index 0b7ca65..34eb6c7 100644
--- a/tests/tivars.py
+++ b/tests/tivars.py
@@ -225,6 +225,9 @@ def test_newlines(self):
         lines = "For(A,1,10", "Disp A", "End"
         self.assertEqual(TIProgram("\n".join(lines)), TIProgram("\r\n".join(lines)))
 
+    def test_byte_literals(self):
+        self.assertEqual(TIProgram.encode(r"\x26\uAA0AXYZ\0"), b'\x26\xAA\x0AXYZ\xbb\xd70')
+
 
 class NumericTests(unittest.TestCase):
     def real_float_test(self, real_type, filename, name, sign, exponent, mantissa, string, dec):
diff --git a/tivars/tokenizer/decoder.py b/tivars/tokenizer/decoder.py
index addd996..098da18 100644
--- a/tivars/tokenizer/decoder.py
+++ b/tivars/tokenizer/decoder.py
@@ -3,6 +3,9 @@
 """
 
 
+from warnings import warn
+
+from tivars.data import Bytes
 from tivars.models import *
 from tivars.tokens.scripts import *
 
@@ -44,10 +47,18 @@ def decode(bytestream: bytes, *,
 
             elif len(curr_bytes) >= 2:
                 if not any(key.startswith(curr_bytes[:1]) for key in tokens.bytes):
-                    raise ValueError(f"unrecognized byte '0x{curr_bytes[0]:x}' at position {index}")
+                    warn(f"Unrecognized byte '{curr_bytes[0]:x}' at position {index}.",
+                         BytesWarning)
+
+                    out.append(b'?' if mode == "ti_ascii" else rf"\x{curr_bytes[0]:x}")
 
                 else:
-                    raise ValueError(f"unrecognized bytes '0x{curr_bytes[0]:x}{curr_bytes[1]:x}' at position {index}")
+                    warn(f"Unrecognized bytes '0x{curr_bytes[0]:x}{curr_bytes[1]:x}' at position {index}.",
+                         BytesWarning)
+
+                    out.append(b'?' if mode == "ti_ascii" else rf"\u{curr_bytes[0]:x}{curr_bytes[1]:x}")
+
+                curr_bytes = b''
 
         elif any(curr_bytes):
             raise ValueError(f"unexpected null byte at position {index}")
diff --git a/tivars/tokenizer/state.py b/tivars/tokenizer/state.py
index 5025229..9b0f3f5 100644
--- a/tivars/tokenizer/state.py
+++ b/tivars/tokenizer/state.py
@@ -37,6 +37,16 @@ def munch(self, string: str, trie: TokenTrie) -> tuple[Token, str, list['Encoder
         :return: A tuple of the output `Token`, the remainder of ``string``, and a list of states to add to the stack
         """
 
+        # Is this a byte literal?
+        if string.startswith(r"\x") or string.startswith(r"\u"):
+            length = 4 if string.startswith(r"\x") else 6
+            string, remainder = string[:length], string[length:]
+            token = Token(bytes.fromhex(string.lstrip(r"\ux")),
+                          {"en": Translation(b'?', string, string, [])},
+                          {"illegal": "true"})
+
+            return token, remainder, self.next(token)
+
         tokens = trie.get_tokens(string)
         if not tokens:
             raise ValueError("no tokenization options exist")