diff --git a/Geometry/CaloTopology/interface/EcalTrigTowerConstituentsMap.h b/Geometry/CaloTopology/interface/EcalTrigTowerConstituentsMap.h
index 2298ab8c2efac..7d3f89cc33727 100644
--- a/Geometry/CaloTopology/interface/EcalTrigTowerConstituentsMap.h
+++ b/Geometry/CaloTopology/interface/EcalTrigTowerConstituentsMap.h
@@ -23,6 +23,8 @@ class EcalTrigTowerConstituentsMap {
   /// Get the tower id for this det id (or null if not known)
   EcalTrigTowerDetId towerOf(const DetId& id) const;
 
+  static EcalTrigTowerDetId barrelTowerOf(const DetId& id);
+
   /// Get the constituent detids for this tower id
   std::vector<DetId> constituentsOf(const EcalTrigTowerDetId& id) const;
 
diff --git a/Geometry/CaloTopology/src/EcalTrigTowerConstituentsMap.cc b/Geometry/CaloTopology/src/EcalTrigTowerConstituentsMap.cc
index a910fcd9e6be1..a972871a06985 100644
--- a/Geometry/CaloTopology/src/EcalTrigTowerConstituentsMap.cc
+++ b/Geometry/CaloTopology/src/EcalTrigTowerConstituentsMap.cc
@@ -5,9 +5,19 @@
 #include "FWCore/MessageLogger/interface/MessageLogger.h"
 
 #include "FWCore/Utilities/interface/Exception.h"
+#include <cassert>
 
 EcalTrigTowerConstituentsMap::EcalTrigTowerConstituentsMap() {}
 
+EcalTrigTowerDetId EcalTrigTowerConstituentsMap::barrelTowerOf(const DetId& id) {
+  assert(id.det() == DetId::Ecal && id.subdetId() == EcalBarrel);
+  //--------------------
+  // Ecal Barrel
+  //--------------------
+  EBDetId myId(id);
+  return myId.tower();
+}
+
 EcalTrigTowerDetId EcalTrigTowerConstituentsMap::towerOf(const DetId& id) const {
   if (id.det() == DetId::Ecal && id.subdetId() == EcalBarrel) {
     //--------------------
diff --git a/SimCalorimetry/EcalEBTrigPrimAlgos/interface/EcalEBTrigPrimTestAlgo.h b/SimCalorimetry/EcalEBTrigPrimAlgos/interface/EcalEBTrigPrimTestAlgo.h
index a56af8869ff3f..3dee30fdca67f 100644
--- a/SimCalorimetry/EcalEBTrigPrimAlgos/interface/EcalEBTrigPrimTestAlgo.h
+++ b/SimCalorimetry/EcalEBTrigPrimAlgos/interface/EcalEBTrigPrimTestAlgo.h
@@ -185,7 +185,8 @@ void EcalEBTrigPrimTestAlgo::fillMap(
     ;
     for (unsigned int i = 0; i < col->size(); ++i) {
       Digi samples((*col)[i]);
-      EcalTrigTowerDetId coarser = (*eTTmap_).towerOf(samples.id());
+      EcalTrigTowerDetId coarser =
+          eTTmap_ ? (*eTTmap_).towerOf(samples.id()) : EcalTrigTowerConstituentsMap::barrelTowerOf(samples.id());
       int index = getIndex(col, coarser);
       int stripnr = findStripNr(samples.id());
 
diff --git a/SimCalorimetry/EcalTrigPrimAlgos/interface/EcalTrigPrimFunctionalAlgo.h b/SimCalorimetry/EcalTrigPrimAlgos/interface/EcalTrigPrimFunctionalAlgo.h
index e08c13ddce0fa..e40adafeeac40 100644
--- a/SimCalorimetry/EcalTrigPrimAlgos/interface/EcalTrigPrimFunctionalAlgo.h
+++ b/SimCalorimetry/EcalTrigPrimAlgos/interface/EcalTrigPrimFunctionalAlgo.h
@@ -305,7 +305,8 @@ void EcalTrigPrimFunctionalAlgo::fillMap(
     LogDebug("EcalTPG") << "Fill mapping, Collection size = " << col->size();
     for (unsigned int i = 0; i < col->size(); ++i) {
       Digi samples((*col)[i]);
-      EcalTrigTowerDetId coarser = (*eTTmap_).towerOf(samples.id());
+      EcalTrigTowerDetId coarser =
+          eTTmap_ ? (*eTTmap_).towerOf(samples.id()) : EcalTrigTowerConstituentsMap::barrelTowerOf(samples.id());
       int index = getIndex(col, coarser);
       int stripnr = findStripNr(samples.id());