diff --git a/src/django_pg_hll/values.py b/src/django_pg_hll/values.py
index 9c539cb..b72d045 100644
--- a/src/django_pg_hll/values.py
+++ b/src/django_pg_hll/values.py
@@ -36,7 +36,7 @@ def __init__(self, data, *args, **extra):
 
         # Psycopg2 returns Binary results as hex string, prefixed by \x but requires bytes for saving.
         if isinstance(data, six.string_types) and data.startswith(r'\x'):
-            data = bytes.fromhex(data[2:])
+            data = bytearray.fromhex(data[2:])
         elif isinstance(data, bytes):
             pass
         else: