diff --git a/ostap/math/models.py b/ostap/math/models.py
index 3aa21f22..4bd00b80 100644
--- a/ostap/math/models.py
+++ b/ostap/math/models.py
@@ -1188,6 +1188,10 @@ def _tf3_getattr_ ( self , attr ) :
                Ostap.Math.GEV                    , 
                Ostap.Math.MPERT                  ,
                #
+               Ostap.Math.Up                     ,
+               Ostap.Math.Hat                    ,
+               Ostap.Math.FupN                   ,
+               #
                Ostap.Math.ECDF                   , 
                #
                Ostap.Math.BSpline                ,