diff --git a/RecoEgamma/PhotonIdentification/interface/PhotonXGBoostEstimator.h b/RecoEgamma/PhotonIdentification/interface/PhotonXGBoostEstimator.h
index fbacb9e5729aa..7252e5116d948 100644
--- a/RecoEgamma/PhotonIdentification/interface/PhotonXGBoostEstimator.h
+++ b/RecoEgamma/PhotonIdentification/interface/PhotonXGBoostEstimator.h
@@ -14,7 +14,7 @@ class PhotonXGBoostEstimator {
                    float sigmaIEtaIEtaIn,
                    float etaWidthIn,
                    float phiWidthIn,
-                   float e2x2In,
+                   float s4In,
                    float etaIn,
                    float hOvrEIn,
                    float ecalPFIsoIn) const;
diff --git a/RecoEgamma/PhotonIdentification/plugins/PhotonXGBoostProducer.cc b/RecoEgamma/PhotonIdentification/plugins/PhotonXGBoostProducer.cc
index e03948ba19a5a..3a22274edb49e 100644
--- a/RecoEgamma/PhotonIdentification/plugins/PhotonXGBoostProducer.cc
+++ b/RecoEgamma/PhotonIdentification/plugins/PhotonXGBoostProducer.cc
@@ -110,6 +110,7 @@ void PhotonXGBoostProducer::produce(edm::StreamID, edm::Event& event, edm::Event
     float hoe = (*hoEMap).find(ref)->val / scEnergy;
     float siEtaiEta = (*sigmaiEtaiEtaMap).find(ref)->val;
     float e2x2 = (*e2x2Map).find(ref)->val;
+    float s4 = e2x2 / scEnergy;
     float iso = (*isoMap).find(ref)->val;
 
     float rawEnergy = ref->superCluster()->rawEnergy();
@@ -124,9 +125,9 @@ void PhotonXGBoostProducer::produce(edm::StreamID, edm::Event& event, edm::Event
     //compute only above threshold used for training and cand filter, else store negative value into the association map.
     if (scEt >= mvaThresholdEt_) {
       if (std::abs(etaSC) < 1.5)
-        xgbScore = mvaEstimatorB_->computeMva(rawEnergy, r9, siEtaiEta, etaW, phiW, e2x2, etaSC, hoe, iso);
+        xgbScore = mvaEstimatorB_->computeMva(rawEnergy, r9, siEtaiEta, etaW, phiW, s4, etaSC, hoe, iso);
       else
-        xgbScore = mvaEstimatorE_->computeMva(rawEnergy, r9, siEtaiEta, etaW, phiW, e2x2, etaSC, hoe, iso);
+        xgbScore = mvaEstimatorE_->computeMva(rawEnergy, r9, siEtaiEta, etaW, phiW, s4, etaSC, hoe, iso);
     }
     mvaScoreMap.insert(ref, xgbScore);
   }
diff --git a/RecoEgamma/PhotonIdentification/src/PhotonXGBoostEstimator.cc b/RecoEgamma/PhotonIdentification/src/PhotonXGBoostEstimator.cc
index 4cc34b3f3077a..8b5cae21c4883 100644
--- a/RecoEgamma/PhotonIdentification/src/PhotonXGBoostEstimator.cc
+++ b/RecoEgamma/PhotonIdentification/src/PhotonXGBoostEstimator.cc
@@ -21,7 +21,7 @@ namespace {
     sigmaIEtaIEta = 2,  // 2
     etaWidth = 3,       // 3
     phiWidth = 4,       // 4
-    e2x2 = 5,           // 5
+    s4 = 5,             // 5
     eta = 6,            // 6
     hOvrE = 7,          // 7
     ecalPFIso = 8,      // 8
@@ -33,7 +33,7 @@ float PhotonXGBoostEstimator::computeMva(float rawEnergyIn,
                                          float sigmaIEtaIEtaIn,
                                          float etaWidthIn,
                                          float phiWidthIn,
-                                         float e2x2In,
+                                         float s4In,
                                          float etaIn,
                                          float hOvrEIn,
                                          float ecalPFIsoIn) const {
@@ -43,7 +43,7 @@ float PhotonXGBoostEstimator::computeMva(float rawEnergyIn,
   var[sigmaIEtaIEta] = sigmaIEtaIEtaIn;
   var[etaWidth] = etaWidthIn;
   var[phiWidth] = phiWidthIn;
-  var[e2x2] = e2x2In;
+  var[s4] = s4In;
   var[eta] = etaIn;
   var[hOvrE] = hOvrEIn;
   var[ecalPFIso] = ecalPFIsoIn;
diff --git a/RecoEgamma/PhotonIdentification/test/test_PhotonMvaXgb.cc b/RecoEgamma/PhotonIdentification/test/test_PhotonMvaXgb.cc
index d0ad3fb50b772..aacede63f294a 100644
--- a/RecoEgamma/PhotonIdentification/test/test_PhotonMvaXgb.cc
+++ b/RecoEgamma/PhotonIdentification/test/test_PhotonMvaXgb.cc
@@ -37,7 +37,7 @@ TEST_CASE("RecoEgamma/PhotonIdentification testXGBPhoton", "[TestPhotonMvaXgb]")
       float xgbScore;
       const float *v = vars_in[i];
       float etaSC = v[6];
-      if (abs(etaSC) < 1.5)
+      if (std::abs(etaSC) < 1.5)
         xgbScore = mvaEstimatorB->computeMva(v[0], v[1], v[2], v[3], v[4], v[5], v[6], v[7], v[8]);
       else
         xgbScore = mvaEstimatorE->computeMva(v[0], v[1], v[2], v[3], v[4], v[5], v[6], v[7], v[8]);