diff --git a/ipapython/ipautil.py b/ipapython/ipautil.py
index 2f4209cff..f83465e25 100644
--- a/ipapython/ipautil.py
+++ b/ipapython/ipautil.py
@@ -1439,13 +1439,13 @@ if six.PY2:
         Decode argument using the file system encoding, as returned by
         `sys.getfilesystemencoding()`.
         """
-        if isinstance(value, six.binary_type):
+        if isinstance(value, bytes):
             return value.decode(sys.getfilesystemencoding())
         elif isinstance(value, str):
             return value
         else:
             raise TypeError("expect {0} or {1}, not {2}".format(
-                six.binary_type.__name__,
+                bytes.__name__,
                 str.__name__,
                 type(value).__name__))
 else:
diff --git a/ipapython/kerberos.py b/ipapython/kerberos.py
index a031fcc0c..5dfd36bbb 100644
--- a/ipapython/kerberos.py
+++ b/ipapython/kerberos.py
@@ -66,7 +66,7 @@ class Principal:
     Container for the principal name and realm according to RFC 1510
     """
     def __init__(self, components, realm=None):
-        if isinstance(components, six.binary_type):
+        if isinstance(components, bytes):
             raise TypeError(
                 "Cannot create a principal object from bytes: {!r}".format(
                     components)