diff --git a/DQM/GEM/plugins/GEMDAQStatusSource.cc b/DQM/GEM/plugins/GEMDAQStatusSource.cc
index e8b978b8311f9..0e6039972b0d4 100644
--- a/DQM/GEM/plugins/GEMDAQStatusSource.cc
+++ b/DQM/GEM/plugins/GEMDAQStatusSource.cc
@@ -394,8 +394,8 @@ void GEMDAQStatusSource::analyze(edm::Event const &event, edm::EventSetup const
       }
 
       Int_t nIdxVFAT = getVFATNumber(gid.station(), gid.roll(), vfatStat->phi());
-      mapStatusVFAT_.FillBits(key3, nIdxVFAT, unQFVFAT);
-      mapStatusVFATPerCh_.FillBits(key4Ch, nIdxVFAT, unQFVFAT);
+      mapStatusVFAT_.FillBits(key3, nIdxVFAT + 1, unQFVFAT);
+      mapStatusVFATPerCh_.FillBits(key4Ch, nIdxVFAT + 1, unQFVFAT);
     }
   }
 
diff --git a/DQM/GEM/plugins/GEMDigiSource.cc b/DQM/GEM/plugins/GEMDigiSource.cc
index f1c3e72821c81..82e1c2ec6b1bf 100644
--- a/DQM/GEM/plugins/GEMDigiSource.cc
+++ b/DQM/GEM/plugins/GEMDigiSource.cc
@@ -187,7 +187,7 @@ void GEMDigiSource::analyze(edm::Event const& event, edm::EventSetup const& even
       for (auto d = digis_in_det.first; d != digis_in_det.second; ++d) {
         // Filling of digi occupancy
         Int_t nIdxVFAT = getVFATNumberByStrip(gid.station(), rId.roll(), d->strip());
-        mapTotalDigi_layer_.Fill(key3, gid.chamber(), nIdxVFAT);
+        mapTotalDigi_layer_.Fill(key3, gid.chamber(), nIdxVFAT + 1);
 
         // Filling of strip
         mapStripOcc_ieta_.Fill(key3, rId.roll());  // Roll