diff --git a/pyzmail/pyzmail/utils.py b/pyzmail/pyzmail/utils.py
index 37d6f71..ea2590a 100644
--- a/pyzmail/pyzmail/utils.py
+++ b/pyzmail/pyzmail/utils.py
@@ -12,9 +12,9 @@
 
 import sys
 
-invalid_chars_in_filename=b'\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f' \
-                          b'\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f' \
-                          b'<>:"/\\|?*\%\''
+invalid_chars_in_filename=b'\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b'\
+                           b'\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17'\
+                           b'\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f<>:"/\\|?*\%\''
 
 invalid_windows_name=[b'CON', b'PRN', b'AUX', b'NUL', b'COM1', b'COM2', b'COM3',
                       b'COM4', b'COM5', b'COM6', b'COM7', b'COM8', b'COM9',