diff --git a/anyconfig/backend/configobj.py b/anyconfig/backend/configobj.py
index 156cf84c..fdd39914 100644
--- a/anyconfig/backend/configobj.py
+++ b/anyconfig/backend/configobj.py
@@ -63,6 +63,6 @@ def dump_impl(cls, data, config_path, **kwargs):
         conf = configobj.ConfigObj(**kwargs)
         conf.update(data)
 
-        conf.write(open(config_path, 'w'))
+        conf.write(open(config_path, 'wb'))
 
 # vim:sw=4:ts=4:et: