diff --git a/config.py b/config.py
index 4db4e127..3c1e9dbb 100644
--- a/config.py
+++ b/config.py
@@ -587,7 +587,7 @@ class MacConfig(AbstractConfig):
         #
         # If we can find where to import the definition of NSCFArray
         # then we could possibly test against that.
-        if res and not isinstance(res, str) and not isinstance(res, int):
+        if res is not None and not isinstance(res, str) and not isinstance(res, int):
             return list(res)
 
         return res