diff --git a/math/minuit2/CMakeLists.txt b/math/minuit2/CMakeLists.txt
index 36246377a34cb..c204e61b78ae7 100644
--- a/math/minuit2/CMakeLists.txt
+++ b/math/minuit2/CMakeLists.txt
@@ -44,7 +44,6 @@ if(CMAKE_PROJECT_NAME STREQUAL ROOT)
       Minuit2/GradientCalculator.h
       Minuit2/HessianGradientCalculator.h
       Minuit2/InitialGradientCalculator.h
-      Minuit2/MPIProcess.h
       Minuit2/MinimumBuilder.h
       Minuit2/MinimumError.h
       Minuit2/MinimumErrorUpdator.h
@@ -91,7 +90,6 @@ if(CMAKE_PROJECT_NAME STREQUAL ROOT)
       Minuit2/MnUserParameterState.h
       Minuit2/MnUserParameters.h
       Minuit2/MnUserTransformation.h
-      Minuit2/MnVectorTransform.h
       Minuit2/ModularFunctionMinimizer.h
       Minuit2/NegativeG2LineSearch.h
       Minuit2/Numerical2PGradientCalculator.h
diff --git a/math/minuit2/inc/Minuit2/MnUserFcn.h b/math/minuit2/inc/Minuit2/MnUserFcn.h
index d1495e711e5e7..890d24e3e4433 100644
--- a/math/minuit2/inc/Minuit2/MnUserFcn.h
+++ b/math/minuit2/inc/Minuit2/MnUserFcn.h
@@ -32,8 +32,6 @@ class MnUserFcn : public MnFcn {
    {
    }
 
-   ~MnUserFcn() override {}
-
    double operator()(const MnAlgebraicVector &) const override;
 
    // Access the parameter transformations.
diff --git a/math/minuit2/inc/Minuit2/MnVectorTransform.h b/math/minuit2/inc/Minuit2/MnVectorTransform.h
deleted file mode 100644
index 67ee8c41a747e..0000000000000
--- a/math/minuit2/inc/Minuit2/MnVectorTransform.h
+++ /dev/null
@@ -1,45 +0,0 @@
-// @(#)root/minuit2:$Id$
-// Authors: M. Winkler, F. James, L. Moneta, A. Zsenei   2003-2005
-
-/**********************************************************************
- *                                                                    *
- * Copyright (c) 2005 LCG ROOT Math team,  CERN/PH-SFT                *
- *                                                                    *
- **********************************************************************/
-
-#ifndef ROOT_Minuit2_MnVectorTransform
-#define ROOT_Minuit2_MnVectorTransform
-
-#include "Minuit2/MnMatrix.h"
-
-#include <vector>
-
-namespace ROOT {
-
-namespace Minuit2 {
-
-class MnVectorTransform {
-
-public:
-   MnVectorTransform() {}
-
-   ~MnVectorTransform() {}
-
-   std::vector<double> operator()(const MnAlgebraicVector &avec) const
-   {
-
-      std::vector<double> result;
-      result.reserve(avec.size());
-
-      for (unsigned int i = 0; i < avec.size(); i++)
-         result.push_back(avec(i));
-
-      return result;
-   }
-};
-
-} // namespace Minuit2
-
-} // namespace ROOT
-
-#endif // ROOT_Minuit2_MnVectorTransform
diff --git a/math/minuit2/src/CMakeLists.txt b/math/minuit2/src/CMakeLists.txt
index aec6a92dd6f4e..630750baf233b 100644
--- a/math/minuit2/src/CMakeLists.txt
+++ b/math/minuit2/src/CMakeLists.txt
@@ -34,7 +34,6 @@ set(MINUIT2_HEADERS
     GradientCalculator.h
     HessianGradientCalculator.h
     InitialGradientCalculator.h
-    MPIProcess.h
     MinimumBuilder.h
     MinimumError.h
     MinimumErrorUpdator.h
@@ -81,7 +80,6 @@ set(MINUIT2_HEADERS
     MnUserParameterState.h
     MnUserParameters.h
     MnUserTransformation.h
-    MnVectorTransform.h
     ModularFunctionMinimizer.h
     NegativeG2LineSearch.h
     Numerical2PGradientCalculator.h
diff --git a/math/minuit2/src/HessianGradientCalculator.cxx b/math/minuit2/src/HessianGradientCalculator.cxx
index 9de4fccbcf9b9..c743369b1be50 100644
--- a/math/minuit2/src/HessianGradientCalculator.cxx
+++ b/math/minuit2/src/HessianGradientCalculator.cxx
@@ -16,7 +16,8 @@
 #include "Minuit2/FunctionGradient.h"
 #include "Minuit2/MnStrategy.h"
 #include "Minuit2/MnPrint.h"
-#include "Minuit2/MPIProcess.h"
+
+#include "./MPIProcess.h"
 
 #include <cmath>
 #include <cassert>
diff --git a/math/minuit2/src/MPIProcess.cxx b/math/minuit2/src/MPIProcess.cxx
index eefdf86c278b7..b5d63522c843b 100644
--- a/math/minuit2/src/MPIProcess.cxx
+++ b/math/minuit2/src/MPIProcess.cxx
@@ -8,7 +8,7 @@
  * Copyright: (C) 2008 by Universita' and INFN, Milan                      *
  ***************************************************************************/
 
-#include "Minuit2/MPIProcess.h"
+#include "./MPIProcess.h"
 
 #include <iostream>
 
diff --git a/math/minuit2/inc/Minuit2/MPIProcess.h b/math/minuit2/src/MPIProcess.h
similarity index 100%
rename from math/minuit2/inc/Minuit2/MPIProcess.h
rename to math/minuit2/src/MPIProcess.h
diff --git a/math/minuit2/src/MnFcn.cxx b/math/minuit2/src/MnFcn.cxx
index dc5b353a95e28..0aaae9198116c 100644
--- a/math/minuit2/src/MnFcn.cxx
+++ b/math/minuit2/src/MnFcn.cxx
@@ -9,7 +9,6 @@
 
 #include "Minuit2/MnFcn.h"
 #include "Minuit2/FCNBase.h"
-#include "Minuit2/MnVectorTransform.h"
 
 namespace ROOT {
 
@@ -24,7 +23,7 @@ double MnFcn::operator()(const MnAlgebraicVector &v) const
 {
    // evaluate FCN converting from from MnAlgebraicVector to std::vector
    fNumCall++;
-   return fFCN(MnVectorTransform()(v));
+   return fFCN(std::vector<double>{v.Data(), v.Data() + v.size()});
 }
 
 // double MnFcn::operator()(const std::vector<double>& par) const {
diff --git a/math/minuit2/src/MnHesse.cxx b/math/minuit2/src/MnHesse.cxx
index 653f9df313c50..a339b8c03e089 100644
--- a/math/minuit2/src/MnHesse.cxx
+++ b/math/minuit2/src/MnHesse.cxx
@@ -21,8 +21,8 @@
 #include "Minuit2/VariableMetricEDMEstimator.h"
 #include "Minuit2/FunctionMinimum.h"
 #include "Minuit2/MnPrint.h"
-#include "Minuit2/MPIProcess.h"
 
+#include "./MPIProcess.h"
 #include "./MnFcnCaller.h"
 
 namespace ROOT {
diff --git a/math/minuit2/src/Numerical2PGradientCalculator.cxx b/math/minuit2/src/Numerical2PGradientCalculator.cxx
index 9391ce120b27c..a511ccc09c7b6 100644
--- a/math/minuit2/src/Numerical2PGradientCalculator.cxx
+++ b/math/minuit2/src/Numerical2PGradientCalculator.cxx
@@ -17,6 +17,9 @@
 #include "Minuit2/MnStrategy.h"
 #include "Minuit2/MnPrint.h"
 
+#include "./MPIProcess.h"
+#include "./MnFcnCaller.h"
+
 #ifdef _OPENMP
 #include <omp.h>
 #endif
@@ -25,10 +28,6 @@
 #include <cassert>
 #include <iomanip>
 
-#include "Minuit2/MPIProcess.h"
-
-#include "./MnFcnCaller.h"
-
 namespace ROOT {
 
 namespace Minuit2 {
diff --git a/math/minuit2/src/ParametricFunction.cxx b/math/minuit2/src/ParametricFunction.cxx
index a4e1d6b6987de..e885c066d7ec3 100644
--- a/math/minuit2/src/ParametricFunction.cxx
+++ b/math/minuit2/src/ParametricFunction.cxx
@@ -13,7 +13,6 @@
 #include "Minuit2/MnUserParameterState.h"
 #include "Minuit2/Numerical2PGradientCalculator.h"
 #include "Minuit2/FunctionGradient.h"
-#include "Minuit2/MnVectorTransform.h"
 #include "Minuit2/MinimumParameters.h"
 
 namespace ROOT {
@@ -40,9 +39,8 @@ std::vector<double> ParametricFunction::GetGradient(std::vector<double> const &x
    FunctionGradient g = gc(MinimumParameters{xVec, mfcn(xVec)});
    const MnAlgebraicVector &grad = g.Vec();
    assert(grad.size() == x.size());
-   MnVectorTransform vt;
    //  std::cout << "Param Function Gradient " << grad << std::endl;
-   return vt(grad);
+   return {grad.Data(), grad.Data() + grad.size()};
 }
 
 } // namespace Minuit2