diff --git a/gui/gui/src/TGSimpleTableInterface.cxx b/gui/gui/src/TGSimpleTableInterface.cxx
index 72b4af4851f687435f5476cd7e1e583060d820c5..d23a90d1c096daaac754df422685462f4f7d2184 100644
--- a/gui/gui/src/TGSimpleTableInterface.cxx
+++ b/gui/gui/src/TGSimpleTableInterface.cxx
@@ -64,9 +64,7 @@ const char *TGSimpleTableInterface::GetValueAsString(UInt_t row, UInt_t column)
 
    // FIXME use template string for string format instead of hardcoded format
 
-   TString str;
-   str.Form("%5.2f", GetValue(row, column));
-   return str.Data();
+   return Form("%5.2f", GetValue(row, column));
 }
 
 //______________________________________________________________________________
@@ -74,9 +72,7 @@ const char *TGSimpleTableInterface::GetRowHeader(UInt_t row)
 {
    // Return a name for the header at row.
 
-   TString str("DRow ");
-   str += row;
-   return str.Data();
+   return Form("DRow %d", row);
 }
 
 //______________________________________________________________________________
@@ -84,7 +80,5 @@ const char *TGSimpleTableInterface::GetColumnHeader(UInt_t column)
 {
    // Return a name for the header at column.
 
-   TString str("DCol ");
-   str += column;
-   return str.Data();
+   return Form("DCol %d", column);
 }
diff --git a/tree/treeplayer/src/TTreeTableInterface.cxx b/tree/treeplayer/src/TTreeTableInterface.cxx
index 883498d7291fd32efce47afcdbfbc098ac001f46..e8a086f598d1a503550fc4c240007c491464696c 100644
--- a/tree/treeplayer/src/TTreeTableInterface.cxx
+++ b/tree/treeplayer/src/TTreeTableInterface.cxx
@@ -362,13 +362,11 @@ const char *TTreeTableInterface::GetValueAsString(UInt_t row, UInt_t column)
    }
    if (column < fNColumns) {
       TTreeFormula *formula = (TTreeFormula *)fFormulas->At(column);
-      TString str;
       if(formula->IsString()) {
-         str.Form("%s", formula->EvalStringInstance());
+         return Form("%s", formula->EvalStringInstance());
       } else {
-         str.Form("%5.2f", (Double_t)formula->EvalInstance());
+         return Form("%5.2f", (Double_t)formula->EvalInstance());
       }
-      return str.Data();
    } else {
       Error("TTreeTableInterface", "Column requested does not exist");
       return 0;
@@ -381,9 +379,7 @@ const char *TTreeTableInterface::GetRowHeader(UInt_t row)
    // Return a string to use as a label for rowheader at column.
 
    if (row < fNRows) {
-      TString str;
-      str.Form("%d", fEntries->GetEntry(row));
-      return str.Data();
+      return Form("%d", fEntries->GetEntry(row));
    } else {
       Error("TTreeTableInterface", "Row requested does not exist");
       return "";