diff --git a/module_build_service/config.py b/module_build_service/config.py

index e2e2fbe..34f62e3 100644

--- a/module_build_service/config.py

+++ b/module_build_service/config.py

@@ -350,22 +350,23 @@ class Config(object):

             raise Exception("Configuration item's name is not allowed: %s" % key)

         # Create the empty self._key attribute, so we can assign to it.

-        setattr(self, "_" + key, None)

-

-        # Create self.key property to access the self._key attribute.

-        # Use the setifok_func if available for the attribute.

-        setifok_func = '_setifok_{}'.format(key)

-        if hasattr(self, setifok_func):

-            setx = lambda self, val: getattr(self, setifok_func)(val)

-        elif value_type == Path:

-            # For paths, expanduser.

-            setx = lambda self, val: setattr(

-                self, "_" + key, os.path.expanduser(val))

-        else:

-            setx = lambda self, val: setattr(self, "_" + key, val)

-        getx = lambda self: getattr(self, "_" + key)

-        delx = lambda self: delattr(self, "_" + key)

-        setattr(Config, key, property(getx, setx, delx))

+        if not hasattr(self, "_" + key):

+            setattr(self, "_" + key, None)

+

+            # Create self.key property to access the self._key attribute.

+            # Use the setifok_func if available for the attribute.

+            setifok_func = '_setifok_{}'.format(key)

+            if hasattr(self, setifok_func):

+                setx = lambda self, val: getattr(self, setifok_func)(val)

+            elif value_type == Path:

+                # For paths, expanduser.

+                setx = lambda self, val: setattr(

+                    self, "_" + key, os.path.expanduser(val))

+            else:

+                setx = lambda self, val: setattr(self, "_" + key, val)

+            getx = lambda self: getattr(self, "_" + key)

+            delx = lambda self: delattr(self, "_" + key)

+            setattr(Config, key, property(getx, setx, delx))

         # managed/registered configuration items

         if key in self._defaults: