diff --git a/bitcoinlib/config/config.py b/bitcoinlib/config/config.py
index b0284f50..8227eb34 100644
--- a/bitcoinlib/config/config.py
+++ b/bitcoinlib/config/config.py
@@ -120,7 +120,7 @@
     1000000000000000000000000: 'Y',
 }
 
-if os.name == 'nt' and locale.getpreferredencoding() != 'UTF-8':
+if os.name == 'nt' and locale.getpreferredencoding().lower() != 'utf-8':
     # TODO: Find a better windows hack
     import _locale
     _locale._getdefaultlocale = (lambda *args: ['en_US', 'utf8'])