diff --git a/compact/drich.xml b/compact/drich.xml
index 02a21110aa1c37b15637218bc6ee95b5e58f5dea..a677e2af7228c4455cdbd030f707cc8fb2557752 100644
--- a/compact/drich.xml
+++ b/compact/drich.xml
@@ -15,12 +15,13 @@
     <constant name="DRICH_rmin1"              value="19.0*cm"/>  <!-- bore radius at dRICh vessel backplane -->
     <constant name="DRICH_wall_thickness"     value="0.5*cm"/>  <!-- thickness of radial walls -->
     <constant name="DRICH_window_thickness"   value="0.1*cm"/>  <!-- thickness of entrance and exit walls -->
-    <!-- snout geometry: cone with front radius rmax0 and back radius of rmax1 -->
-    <constant name="DRICH_SnoutLength"        value="50.0*cm"/>
-    <constant name="DRICH_rmax0"              value="110.0*cm"/>
-    <constant name="DRICH_rmax1"              value="125.0*cm"/>
     <!-- tank geometry: cylinder, holding the majority of detector components -->
     <constant name="DRICH_rmax2"              value="200*cm"/>  <!-- cylinder radius; 20 cm gap between dRICh and HCalBarrel -->
+    <!-- snout geometry: cone with front radius rmax0 and back radius of rmax1 -->
+    <constant name="DRICH_SnoutLength"        value="50.0*cm"/>
+    <constant name="DRICH_SnoutSlope"         value="DRICH_rmax2 / (DRICH_zmin + DRICH_Length)"/>
+    <constant name="DRICH_rmax0"              value="DRICH_SnoutSlope * DRICH_zmin"/>
+    <constant name="DRICH_rmax1"              value="DRICH_SnoutSlope * ( DRICH_zmin + DRICH_SnoutLength)"/>
     <!-- additional parameters -->
     <constant name="DRICH_aerogel_thickness"  value="4.0*cm"/>  <!-- aerogel thickness -->
     <constant name="DRICH_sensor_size"        value="48.0*mm"/> <!-- sensor side length -->