diff --git a/python/damask/_result.py b/python/damask/_result.py
index 019f9c87d..f47a7da80 100644
--- a/python/damask/_result.py
+++ b/python/damask/_result.py
@@ -354,7 +354,7 @@ class Result:
             else:
                 what_,datasets_ = v
                 dup = self._manage_view('set',what_,datasets_)
-            if protected is True:
+            if not protected:
                 print(util.warn('Warning: Modification of existing datasets allowed!'))
             dup._protected = protected
         else: