diff --git a/tsg_util/updateTsgStructWithCalCoeff.m b/tsg_util/updateTsgStructWithCalCoeff.m
index 4b5f6d0f3078807903b7e6c43e2598957e519f43..09fdeca89b44085d02f86de7f320597a4863ffaa 100644
--- a/tsg_util/updateTsgStructWithCalCoeff.m
+++ b/tsg_util/updateTsgStructWithCalCoeff.m
@@ -33,6 +33,7 @@ pref = tsg.preference.coeff_type_value;
 % --------------------------
 for i = 1:numel(var)
   if isempty(tsg.(var{i})) 
+    tsg.([var{i} '_CONV']) = [];
     for j = 1:tsg.dim.CALCOEF
       tsg.(var{i})(j) = NaN;
       tsg.([var{i} '_CONV']) = ...