diff --git a/data/params.txt b/data/params.txt
index 5d8042c..67df179 100644
--- a/data/params.txt
+++ b/data/params.txt
@@ -240,7 +240,8 @@ step = 0.2           // length of one step in cascade
 xsec = 1 //model of cross sections in cascade: 0 - metropolis, 1 - oset
 kaskada_w = 7
 
-  formation_zone = fz
+  formation_zone = fz-new
+# formation_zone = fz     //
 # formation_zone = nofz   //
 # formation_zone = fz     //
 # formation_zone = trans  //
diff --git a/src/params.xml b/src/params.xml
index 6b23b14..7d1691a 100644
--- a/src/params.xml
+++ b/src/params.xml
@@ -374,7 +374,7 @@
   <param name="kaskada_writeall" type="checkbox" ctype="bool" default="0">
     <description><![CDATA[Store all intermediate FSI particles int the event::all vector]]></description>
   </param> 
-  <param name="formation_zone" type="select" ctype="string" default="fz">
+  <param name="formation_zone" type="select" ctype="string" default="fz-new">
     <description><![CDATA[Name of formation zone model]]></description>
     <options>
       <option key="fz"><![CDATA[fz - ]]></option>