diff --git a/Detector/DetCRD/compact/CRD_o1_v01/CRD_Dimensions_v01_01.xml b/Detector/DetCRD/compact/CRD_o1_v01/CRD_Dimensions_v01_01.xml
index ab7bb56c75e83593109af5a19d291dfa96b9b455..4291475b54acb191083bb344011b60a2397273f8 100644
--- a/Detector/DetCRD/compact/CRD_o1_v01/CRD_Dimensions_v01_01.xml
+++ b/Detector/DetCRD/compact/CRD_o1_v01/CRD_Dimensions_v01_01.xml
@@ -95,7 +95,7 @@
     <constant name="SIT1_inner_radius"   value="152.90*mm"/>
     <constant name="SIT1_half_length"    value="368.00*mm"/>
     <constant name="SIT2_inner_radius"   value="InnerTracker_outer_radius + env_safety"/>
-    <constant name="SIT2_half_length"    value="InnerTracker_half_length"/>
+    <constant name="SIT2_half_length"    value="MainTracker_half_length"/>
 
     <constant name="FTD_BeamPipe_cable_clearance"     value="10*mm"/> 
     <constant name="FTD_BeamPipe_gap"     value="15*mm"/>