diff --git a/dns/rdata.py b/dns/rdata.py
index 527b1bd0..12f3b6f3 100644
--- a/dns/rdata.py
+++ b/dns/rdata.py
@@ -51,7 +51,7 @@ def _wordbreak(data, chunksize=_chunksize):
                       in range(0, len(data), chunksize)]).decode()
 
 
-def _hexify(data, chunksize=_chunksize):
+def _hexify(data, chunksize=_chunksize, **kw):
     """Convert a binary string into its hex encoding, broken up into chunks
     of chunksize characters separated by a space.
     """
@@ -59,7 +59,7 @@ def _hexify(data, chunksize=_chunksize):
     return _wordbreak(binascii.hexlify(data), chunksize)
 
 
-def _base64ify(data, chunksize=_chunksize):
+def _base64ify(data, chunksize=_chunksize, **kw):
     """Convert a binary string into its base64 encoding, broken up into chunks
     of chunksize characters separated by a space.
     """