diff --git a/topside/silicon_tracker.xml b/topside/silicon_tracker.xml
index adf1dfc1494bd1d2873a03e639029802f1e457e3..723292d60466431d72f950be500111435e834336 100644
--- a/topside/silicon_tracker.xml
+++ b/topside/silicon_tracker.xml
@@ -860,15 +860,15 @@
 
   <readouts>
     <readout name="SiTrackerBarrelHits">
-      <segmentation type="CartesianGridXY" grid_size_x="0.10*mm" grid_size_y="0.10*mm" />
+      <segmentation type="CartesianGridXY" grid_size_x="0.10*mm" grid_size_y="0.50*mm" />
       <id>system:8,barrel:2,layer:4,module:12,sensor:2,x:32:-16,y:-16</id>
     </readout>
     <readout name="SiTrackerEndcapHits">
-      <segmentation type="CartesianGridXY" grid_size_x="0.10*mm" grid_size_y="0.10*mm" />
+      <segmentation type="CartesianGridXY" grid_size_x="0.10*mm" grid_size_y="0.50*mm" />
       <id>system:8,barrel:2,layer:4,module:12,sensor:2,x:32:-16,y:-16</id>
     </readout>
     <readout name="SiTrackerForwardHits">
-      <segmentation type="CartesianGridXY" grid_size_x="0.10*mm" grid_size_y="0.10*mm" />
+      <segmentation type="CartesianGridXY" grid_size_x="0.10*mm" grid_size_y="0.50*mm" />
       <id>system:8,barrel:2,layer:4,module:12,sensor:2,x:32:-16,y:-16</id>
     </readout>
   </readouts>