diff --git a/compact/ce_GEM.xml b/compact/ce_GEM.xml
index 33d018d871c603b70ef74fd92023b16d007326a7..76a6758d5096476583b7c65cdc9618626afa64cc 100644
--- a/compact/ce_GEM.xml
+++ b/compact/ce_GEM.xml
@@ -15,7 +15,8 @@
     <constant name="ce_GEM_length"          value="30.0 * cm"/>
     <constant name="ce_GEM_x_pos"           value="0.0 * cm"/>
     <constant name="ce_GEM_y_pos"           value="0.0 * cm"/>
-    <constant name="ce_GEM_z_pos"           value="-Solenoid_length/2.0 + ce_GEM_length/2.0"/>
+    <!--<constant name="ce_GEM_z_pos"           value="-Solenoid_length/2.0 + ce_GEM_length/2.0"/>-->
+    <constant name="ce_GEM_z_pos"           value="-CrystalEndcap_z_pos - CrystalBox_z_length"/>
     <constant name="ce_GEM_layer"           value="8"/>
     <constant name="ce_GEM_layer_thickness" value="1.0 * cm"/>
   </define>