diff --git a/ostap/fitting/fithelpers.py b/ostap/fitting/fithelpers.py
index 0178fccf..d5fa9862 100644
--- a/ostap/fitting/fithelpers.py
+++ b/ostap/fitting/fithelpers.py
@@ -1735,7 +1735,7 @@ def vars_to_asymmetry ( self             ,
         asym_var = self.vars_asymmetry (
             var1               , ## first vatiable 
             var2               , ## second variable 
-            scale = scale      , ## scale
+            scale = asym_scale , ## scale
             name  = asym_name  ,
             title = asym_title )