diff --git a/html5lib/_inputstream.py b/html5lib/_inputstream.py
index c20e94fd..1635a208 100644
--- a/html5lib/_inputstream.py
+++ b/html5lib/_inputstream.py
@@ -5,6 +5,7 @@
 
 import codecs
 import re
+from io import BytesIO, StringIO
 
 import webencodings
 
@@ -12,13 +13,6 @@
 from .constants import _ReparseException
 from . import _utils
 
-from io import StringIO
-
-try:
-    from io import BytesIO
-except ImportError:
-    BytesIO = StringIO
-
 # Non-unicode versions of constants for use in the pre-parser
 spaceCharactersBytes = frozenset([item.encode("ascii") for item in spaceCharacters])
 asciiLettersBytes = frozenset([item.encode("ascii") for item in asciiLetters])