diff --git a/site_ansto/instrument/sans/config/parameters/parameters.tcl b/site_ansto/instrument/sans/config/parameters/parameters.tcl
index 183ab075..1a55eb98 100644
--- a/site_ansto/instrument/sans/config/parameters/parameters.tcl
+++ b/site_ansto/instrument/sans/config/parameters/parameters.tcl
@@ -11,6 +11,7 @@ foreach {var lname type priv units klass} {
   BeamCenterZ      BeamCenterZ        float user     mm   reduce
   BeamStop         BeamStop           int   user     none parameter
   BSdiam           BSdiam             float user     mm   parameter
+  DetPosYOffset    DetPosYOffset      float user     mm   parameter
   EApPosY          EApPosY            float user     mm   parameter
   EndFacePosY      EndFacePosY        float readonly mm   parameter
   GuideConfig      GuideConfig        text  user     none parameter
@@ -76,8 +77,9 @@ sicslist setatt L1 units mm
 
 ::utility::macro::getset float L2 {} {
   set detpy [SplitReply [det]]
+  set detpyos [SplitReply [DetPosYOffset]]
   set sapy [SplitReply [samy]]
-  return [sicsmsgfmt [expr {$detpy - $sapy}]]
+  return [sicsmsgfmt [expr {$detpy + $detpyos - $sapy}]]
 }
 sicslist setatt L2 long_name L2
 sicslist setatt L2 klass parameter
@@ -110,6 +112,7 @@ namespace eval parameters {
 	set paramlist {
 		AttFactor
 		BSdiam
+    DetPosYOffset    
 		EApPosY
 		EApShape
 		EApX