diff --git a/compact/definitions.xml b/compact/definitions.xml
index d5def7b5cc2c042981c194a369c5d2f07f518cad..d13e22e6e08b20efd06d833556de18f4bc4bf127 100644
--- a/compact/definitions.xml
+++ b/compact/definitions.xml
@@ -379,7 +379,7 @@
 
       The cb_CTD_* parameters can probably be moved to the detector specific xml file.
     </comment>
-    <constant name="cb_CTD_rmin"   value="SiliconTrackerInnerRadius"/>
+    <constant name="cb_CTD_rmin"   value="SiliconTrackerInnerRadius + 70.0 * mm"/>
     <constant name="cb_CTD_rmax"   value="SiliconTrackerOuterRadius"/>
     <constant name="cb_CTD_zmax"   value="SiliconTrackerOuterBarrel_zmax"/>
     <constant name="cb_CTD_length" value="SiliconTrackerOuterBarrelLength"/>