diff --git a/compact/definitions.xml b/compact/definitions.xml
index 3b40028d2aa3b2655e43729c071fb3ac076740a6..cc2e41d49efcd44cd9f54ae1c9aae16c68c8036a 100644
--- a/compact/definitions.xml
+++ b/compact/definitions.xml
@@ -490,7 +490,7 @@ end of the solenoid coils.
 EcalEndcapP_rmin and EcalEndcapN_rmin need to be set in sync with the forward and backward detectors.
     </documentation>
     <constant name="EcalEndcapP_rmin"                      value="200.0*mm"/>
-    <constant name="EcalEndcapN_rmin"                      value="5*cm"/>
+    <constant name="EcalEndcapN_rmin"                      value="max((EcalEndcapN_zmin + EcalEndcapN_length) * tan(abs(CrossingAngle)) + 12.5 * mm, 5*cm)"/>
     <constant name="EcalEndcapN_rmax"                      value="BarrelTracking_rmax"/>
 
     <documentation>