diff --git a/src/classes/PRunMuMinus.cpp b/src/classes/PRunMuMinus.cpp
index 5440e154d..e1fb4707d 100644
--- a/src/classes/PRunMuMinus.cpp
+++ b/src/classes/PRunMuMinus.cpp
@@ -36,11 +36,12 @@
 #endif
 
 #include <iostream>
+#include <string>
+#include <vector>
 
 #include <TString.h>
-#include <TObjArray.h>
-#include <TObjString.h>
 
+#include "PStringUtils.h"
 #include "PRunMuMinus.h"
 
 //--------------------------------------------------------------------------
@@ -448,18 +449,15 @@ UInt_t PRunMuMinus::GetNoOfFitBins()
  */
 void PRunMuMinus::SetFitRangeBin(const TString fitRange)
 {
-  TObjArray *tok = nullptr;
-  TObjString *ostr = nullptr;
   TString str;
   Ssiz_t idx = -1;
   Int_t offset = 0;
 
-  tok = fitRange.Tokenize(" \t");
+  std::vector<std::string> tok = PStringUtils::Split(fitRange.Data(), " \t");
 
-  if (tok->GetEntries() == 3) { // structure FIT_RANGE fgb+n0 lgb-n1
+  if (tok.size() == 3) { // structure FIT_RANGE fgb+n0 lgb-n1
     // handle fgb+n0 entry
-    ostr = dynamic_cast<TObjString*>(tok->At(1));
-    str = ostr->GetString();
+    str = tok[1];
     // check if there is an offset present
     idx = str.First("+");
     if (idx != -1) { // offset present
@@ -470,8 +468,7 @@ void PRunMuMinus::SetFitRangeBin(const TString fitRange)
     fFitStartTime = (fGoodBins[0] + offset - fT0s[0]) * fTimeResolution;
 
     // handle lgb-n1 entry
-    ostr = dynamic_cast<TObjString*>(tok->At(2));
-    str = ostr->GetString();
+    str = tok[2];
     // check if there is an offset present
     idx = str.First("-");
     if (idx != -1) { // offset present
@@ -480,16 +477,15 @@ void PRunMuMinus::SetFitRangeBin(const TString fitRange)
         offset = str.Atoi();
     }
     fFitEndTime = (fGoodBins[1] - offset - fT0s[0]) * fTimeResolution;
-  } else if ((tok->GetEntries() > 3) && (tok->GetEntries() % 2 == 1)) { // structure FIT_RANGE fgb[+n00] lgb[-n01] [fgb[+n10] lgb[-n11] ... fgb[+nN0] lgb[-nN1]]
-    Int_t pos = 2*(fRunNo+1)-1;
+  } else if ((tok.size() > 3) && (tok.size() % 2 == 1)) { // structure FIT_RANGE fgb[+n00] lgb[-n01] [fgb[+n10] lgb[-n11] ... fgb[+nN0] lgb[-nN1]]
+    UInt_t pos = 2*(fRunNo+1)-1;
 
-    if (pos + 1 >= tok->GetEntries()) {
+    if (pos + 1 >= tok.size()) {
       std::cerr << std::endl << ">> PRunMuMinus::SetFitRangeBin(): **ERROR** invalid FIT_RANGE command found: '" << fitRange << "'";
       std::cerr << std::endl << ">> will ignore it. Sorry ..." << std::endl;
     } else {
       // handle fgb+n0 entry
-      ostr = dynamic_cast<TObjString*>(tok->At(pos));
-      str = ostr->GetString();
+      str = tok[pos];
       // check if there is an offset present
       idx = str.First("+");
       if (idx != -1) { // offset present
@@ -500,8 +496,7 @@ void PRunMuMinus::SetFitRangeBin(const TString fitRange)
       fFitStartTime = (fGoodBins[0] + offset - fT0s[0]) * fTimeResolution;
 
       // handle lgb-n1 entry
-      ostr = dynamic_cast<TObjString*>(tok->At(pos+1));
-      str = ostr->GetString();
+      str = tok[pos+1];
       // check if there is an offset present
       idx = str.First("-");
       if (idx != -1) { // offset present
@@ -515,11 +510,6 @@ void PRunMuMinus::SetFitRangeBin(const TString fitRange)
     std::cerr << std::endl << ">> PRunMuMinus::SetFitRangeBin(): **ERROR** invalid FIT_RANGE command found: '" << fitRange << "'";
     std::cerr << std::endl << ">> will ignore it. Sorry ..." << std::endl;
   }
-
-  // clean up
-  if (tok) {
-    delete tok;
-  }
 }
 
 //--------------------------------------------------------------------------