diff --git a/Control/CalypsoExample/BarcodeChecker/python/BarcodeCheckerAlg.py b/Control/CalypsoExample/BarcodeChecker/python/BarcodeCheckerAlg.py
index cc92bd8ac574dbaccfe522366666462b6219d988..f74d84b7b2145261d8298fc99f32e38717549507 100644
--- a/Control/CalypsoExample/BarcodeChecker/python/BarcodeCheckerAlg.py
+++ b/Control/CalypsoExample/BarcodeChecker/python/BarcodeCheckerAlg.py
@@ -24,7 +24,8 @@ class BarcodeCheckerAlg(PyAthena.Alg):
         for mcEvt in evtCollection:
             for mcParticle in mcEvt.particles:
                 barCode = mcParticle.barcode()
-                self.maxLow = max(self.maxLow, barCode%200000)
+                if barCode%1000000 <= 200000:
+                    self.maxLow = max(self.maxLow, barCode%1000000)
                 if barCode%1000000 > 200000:
                     self.maxMid = max(self.maxMid, barCode%1000000 - 200000)
                 self.maxHi = max(self.maxHi, barCode//1000000)