diff --git a/calorimeters/ZDC_example.xml b/calorimeters/ZDC_example.xml
index fce8c083eb7d8030191fb1f81a93fb1ef511f9be..e7027926310532431d2eac6db20f89460a6d9fa2 100644
--- a/calorimeters/ZDC_example.xml
+++ b/calorimeters/ZDC_example.xml
@@ -31,12 +31,12 @@
     		<constant name="offset_ZDC"    value="5.0*mm"/>
 		<constant name="st_length"     value="20.0*mm"/>
 		<constant name="lt_length"     value="40.0*mm"/>
-		<constant name="st_ZDC_x_pos"  value="0.60*m"/>
+		<constant name="st_ZDC_x_pos"  value="0.0*m"/>   <!-- value="0.60*m"  -->
 		<constant name="st_ZDC_y_pos"  value="0.0*m"/>
-		<constant name="st_ZDC_z_pos"  value="34.0*m"/>
-		<constant name="lt_ZDC_x_pos"  value="0.60*m"/>
+		<constant name="st_ZDC_z_pos"  value="1.0*m"/>   <!-- value="34.0*m"  -->
+		<constant name="lt_ZDC_x_pos"  value="0.0*m"/>   <!-- value="0.60*m"  -->
 		<constant name="lt_ZDC_y_pos"  value="offset_ZDC + (st_length+lt_length)/sqrt(2)"/>
-        	<constant name="lt_ZDC_z_pos"  value="34.0*m"/>
+        	<constant name="lt_ZDC_z_pos"  value="1.0*m"/>  <!-- value="34.0*m"  -->
   	</define>
 
   <limits>
diff --git a/calorimeters/simple_checking.cxx b/calorimeters/simple_checking.cxx
index 774317ffbacf23cc093a55b6d4afaf9fcf09727a..158f4f781b320fc18bf704a92b1d78fa10cecf76 100644
--- a/calorimeters/simple_checking.cxx
+++ b/calorimeters/simple_checking.cxx
@@ -108,7 +108,7 @@ std::cout << "testing 3\n";
 std::cout << "testing 4\n";
   auto h0 = d1.Histo1D(TH1D("h0", "nhits; ", 20, 0,20), "nhits");
 
-  auto n0 = d1.Filter([](int n){ return (n>=0); },{"nhits"}).Count();
+  auto n0 = d1.Filter([](int n){ return (n>0); },{"nhits"}).Count();
 
   TCanvas* c = new TCanvas();