diff --git a/src/backports/configparser/__init__.py b/src/backports/configparser/__init__.py
index 06d7a08..0a6c3e7 100644
--- a/src/backports/configparser/__init__.py
+++ b/src/backports/configparser/__init__.py
@@ -684,7 +684,7 @@ def read(self, filenames, encoding=None):
 
         Return list of successfully read files.
         """
-        if PY2 and isinstance(filenames, bytes):
+        if PY2 and isinstance(filenames, bytes) and sys.py3kwarning:
             # we allow for a little unholy magic for Python 2 so that
             # people not using unicode_literals can still use the library
             # conveniently