diff --git a/pisi/constants.py b/pisi/constants.py
index e476d1a8..58427016 100644
--- a/pisi/constants.py
+++ b/pisi/constants.py
@@ -82,10 +82,10 @@ class Constants:
         return getattr(self.__c, attr)
 
     def __setattr__(self, attr, value):
-        return setattr(self.__c, attr, value)
+        setattr(self.__c, attr, value)
 
     def __delattr__(self, attr):
-        return delattr(self.__c, attr)
+        delattr(self.__c, attr)
 
 # singleton for easy access here
 const = Constants()
diff --git a/pisi/context.py b/pisi/context.py
index b96ea721..cc496698 100644
--- a/pisi/context.py
+++ b/pisi/context.py
@@ -61,4 +61,4 @@ class BuildContext(object):
         return getattr(self.__instance, attr)
 
     def __setattr__(self, attr, value):
-        return setattr(self.__instance, attr, value)
+        setattr(self.__instance, attr, value)