diff --git a/TPC/TPCbase/AliTPCCalROC.h b/TPC/TPCbase/AliTPCCalROC.h
index 08b09594313..651064fc9ea 100644
--- a/TPC/TPCbase/AliTPCCalROC.h
+++ b/TPC/TPCbase/AliTPCCalROC.h
@@ -10,6 +10,7 @@
 #include <TMath.h>
 #include <AliTPCROC.h>
 #include "TLinearFitter.h"
+#include <TMath.h>
 
 class TH1F;
 class TH2F;
@@ -35,8 +36,8 @@ class AliTPCCalROC : public TNamed {
   UInt_t        GetNchannelsMedium() const     { return (fSector<36)? 0: fkIndexes[64];};
   Bool_t        IsInRange(UInt_t row, UInt_t pad) { return (row<fNRows)? (fkIndexes[row]+pad)<fNChannels:kFALSE;}
   UInt_t        GetNPads(UInt_t row)  const     { return (row<fNRows)? AliTPCROC::Instance()->GetNPads(fSector,row):0;};
-  Float_t      GetValue(UInt_t row, UInt_t pad) const { return ( (row<fNRows) && (fkIndexes[row]+pad)<fNChannels)? fData[fkIndexes[row]+pad]: 0; };
-  Float_t      GetValue(UInt_t channel) const { return  fData[channel]; };
+  Float_t      GetValue(UInt_t channel) const { return  TMath::IsNaN(fData[channel]) ? 0. : fData[channel]; };
+  Float_t      GetValue(UInt_t row, UInt_t pad) const { return ( (row<fNRows) && (fkIndexes[row]+pad)<fNChannels)? GetValue(fkIndexes[row]+pad): 0; };
   void         SetValue(UInt_t row, UInt_t pad, Float_t vd) { if ( row<fNRows && (fkIndexes[row]+pad)<fNChannels)fData[fkIndexes[row]+pad]= vd; }
   void         SetValue(UInt_t channel, Float_t vd) {fData[channel]= vd; }
   void         Reset();
diff --git a/TPC/TPCsim/AliTPC.cxx b/TPC/TPCsim/AliTPC.cxx
index 19fc60d6bac..d5c8554fc77 100644
--- a/TPC/TPCsim/AliTPC.cxx
+++ b/TPC/TPCsim/AliTPC.cxx
@@ -1938,11 +1938,6 @@ void AliTPC::DigitizeRow(Int_t irow,Int_t isec,TObjArray **rows)
       if(fDigitsSwitch == 0){	
 	Float_t gain = gainROC->GetValue(irow,ip);  // get gain for given - pad-row pad	
 	Float_t noisePad = noiseROC->GetValue(irow,ip);	
-        //protection for nan
-        if ( TMath::IsNaN(noisePad) ){
-          noisePad=0.;
-        }
-
 	//
 	q*=gain;
 	q+=GetNoise()*noisePad;