diff --git a/site_ansto/instrument/bilby/config/anticollider/anticollider.tcl b/site_ansto/instrument/bilby/config/anticollider/anticollider.tcl
index 654b2446..34f5f639 100644
--- a/site_ansto/instrument/bilby/config/anticollider/anticollider.tcl
+++ b/site_ansto/instrument/bilby/config/anticollider/anticollider.tcl
@@ -3,16 +3,13 @@
 fileeval $cfPath(anticollider)/anticollider_common.tcl
 
 namespace eval ::anticollider {
-  set guide_posit 1
-  set aperture_posit 2
-  set apD10_posit 1
   set coltol 0.5
   set aptol 0.1
 
   for {set n 1} {$n <= 8} {incr n} {
     foreach {col ap} "pc$n ap$n" {
-      set col_limit [expr [SplitReply [$col posit2unit $aperture_posit]] - $coltol]
-      set ap_limit [expr [SplitReply [$ap posit2unit $apD10_posit]] - $aptol]
+      set col_limit [expr [SplitReply [$col posit2unit apertures]] - $coltol]
+      set ap_limit [expr [SplitReply [$ap posit2unit out]] + $aptol]
       set acrule [subst {forbid {5 inf} for $ap when $col in {-inf $col_limit} }]
       lappend ::anticollider::veto_rules $acrule
       set acrule [subst {forbid {-inf $col_limit} for $col when $ap in {$ap_limit inf} }]