diff --git a/compact/ffi_ZDC.xml b/compact/ffi_ZDC.xml
index 36638f190574fc06417d756cfd44213bde496a88..964c761a3a81fb379b9c0ab931ad6ec447383b1a 100644
--- a/compact/ffi_ZDC.xml
+++ b/compact/ffi_ZDC.xml
@@ -26,7 +26,7 @@
   <readouts>
     <readout name="ffi_ZDC_Hits">
       <segmentation type="CartesianGridXY" grid_size_x="1.0*mm" grid_size_y="1.0*mm" />
-      <id>system:8,sector:6,module:6,x:32:-16,y:-16</id>  
+      <id>system:8,sector:8,module:14,x:32:-16,y:-16</id>  
     </readout>
   </readouts>
 
diff --git a/src/ffi_ZDC.cpp b/src/ffi_ZDC.cpp
index 0ea018719bb7f4b31264b71ebae7fb322979daa7..61ca838b5a701dde41475fb106b6756a3d7c291a 100644
--- a/src/ffi_ZDC.cpp
+++ b/src/ffi_ZDC.cpp
@@ -70,7 +70,7 @@ static Ref_t createDetector(Detector& desc, xml_h e, SensitiveDetector sens)
       k++;
       string module_name = detName + _toString(k,"_ECAL_Phys_%d"); 
       PlacedVolume pv_mod = detVol.placeVolume(modVol, Position(mod_x,mod_y,mod_z));
-      pv_mod.addPhysVolID("sector", 1).addPhysVolID("module",k);
+      pv_mod.addPhysVolID("sector", 1).addPhysVolID("module",k+1);
     }
   }