diff --git a/bliss/config/settings.py b/bliss/config/settings.py
index 3932882f404092440fff40e46e6958c570e6af0c..79c86059195a28e4acc7602ced8454e77135c9d1 100644
--- a/bliss/config/settings.py
+++ b/bliss/config/settings.py
@@ -96,8 +96,10 @@ def write_decorator_dict(func):
                 raise TypeError('can only be dict')
 
             if values is not None:
+                new_dict = dict()
                 for k, v in values.iteritems():
-                    values[k] = self._write_type_conversion(v)
+                    new_dict[k] = self._write_type_conversion(v)
+                values = new_dict
         return func(self, values, **keys)
     return _write