diff --git a/Control/AthenaMonitoringKernel/src/HistogramFiller/OfflineHistogramProvider.h b/Control/AthenaMonitoringKernel/src/HistogramFiller/OfflineHistogramProvider.h
index 76f3e8b650f1621fdd921a48ad47f901f987669e..22322a685b7372be2a0541b4f1b9c2d121d3cf88 100644
--- a/Control/AthenaMonitoringKernel/src/HistogramFiller/OfflineHistogramProvider.h
+++ b/Control/AthenaMonitoringKernel/src/HistogramFiller/OfflineHistogramProvider.h
@@ -75,8 +75,8 @@ namespace Monitored {
       if ( period == HistogramDef::RunPeriod::Run ) {
         lbString = "";
       } else if ( period == HistogramDef::RunPeriod::LowStat ) {
-        const unsigned lbBase = lumiBlock-(lumiBlock%20);
-        lbString = "/lowStat_LB"+std::to_string(lbBase+1)+"-"+std::to_string(lbBase+20);
+        const unsigned lbBase = lumiBlock-(((int64_t)lumiBlock-1)%20);
+        lbString = "/lowStat_LB"+std::to_string(lbBase)+"-"+std::to_string(lbBase+19);
       } else {
         lbString = "/lb_"+std::to_string(lumiBlock);
       }
diff --git a/Control/AthenaMonitoringKernel/test/LumiblockHistogramProviderTestSuite.cxx b/Control/AthenaMonitoringKernel/test/LumiblockHistogramProviderTestSuite.cxx
index 80e8933517b4e42311e70e5a376ec7b83046362d..fb0b4714190b3dfbbded8f1f2a0302ba9f263364 100644
--- a/Control/AthenaMonitoringKernel/test/LumiblockHistogramProviderTestSuite.cxx
+++ b/Control/AthenaMonitoringKernel/test/LumiblockHistogramProviderTestSuite.cxx
@@ -121,7 +121,7 @@ class LumiblockHistogramProviderTestSuite {
 
     void test_shouldCreateNewHistogramWithUpdatedLumiBlock() {
       auto expectedFlow = {
-        make_tuple(100, 100000, "/run_100000/lowStat_LB101-120/"),
+        make_tuple(100, 100000, "/run_100000/lowStat_LB81-100/"),
         make_tuple(125, 200000, "/run_200000/lowStat_LB121-140/"),
       };