diff --git a/README/ReleaseNotes/v642/index.md b/README/ReleaseNotes/v642/index.md
index 317fa53b195d1..a78bc136acc84 100644
--- a/README/ReleaseNotes/v642/index.md
+++ b/README/ReleaseNotes/v642/index.md
@@ -76,6 +76,7 @@ The `TMVA_SOFIE_GNN` tutorials have been migrated to this workflow and produce i
 * The header `RStringView.h` deprecated in ROOT 6.14  will now emit warnings and will be fully removed after ROOT 6.44. Use `ROOT/RStringView.hxx` instead.
 * The header `snprintf.h` is deprecated (will emit warnings) and will be removed in ROOT 6.44. Use instead `<cstdio>`.
 * The header `Strlen.h` is deprecated and will be removed in ROOT 6.44. Use `<cstring>` directly as a replacement. `NEED_STRING` macro should not be defined or an error will be raised.
+* The header `Varargs.h` and the macro `R__VA_COPY` are deprecated and will be removed in ROOT 6.46, use `<cstdarg>` instead.
 * The header `Rstrstream.h` is deprecated and will be removed after ROOT 6.44, use instead `<sstream>`.
 
 ## Build System
diff --git a/cmake/unix/module.modulemap b/cmake/unix/module.modulemap
index b3cb9b146bf12..f0d8eb61b616a 100644
--- a/cmake/unix/module.modulemap
+++ b/cmake/unix/module.modulemap
@@ -32,10 +32,6 @@ module ROOT_Rtypes {
 // They are mainly needed for ROOT stage1 build.
 module ROOT_Foundation_Stage1_NoRTTI  {
   module "ESTLType.h" { header "ESTLType.h" export * }
-  // Varargs contains a lot of macros for supporting the obsolete va_args.
-  // FIXME: We may want to drop this when we reimplement all uses to use variadic
-  // templates.
-  module "Varargs.h" { header "Varargs.h" export * }
   module "TClassEdit.h" { header "TClassEdit.h" export * }
   module "TIsAProxy.h" { header "TIsAProxy.h" export * }
   module "TVirtualIsAProxy.h" { header "TVirtualIsAProxy.h" export * }
diff --git a/core/base/inc/RQ_OBJECT.h b/core/base/inc/RQ_OBJECT.h
index 07787f9c7e2b3..62a5757b579bd 100644
--- a/core/base/inc/RQ_OBJECT.h
+++ b/core/base/inc/RQ_OBJECT.h
@@ -13,7 +13,7 @@
 #define ROOT_RQ_OBJECT
 
 #include <TQObject.h>
-#include <Varargs.h>
+#include <cstdarg>
 
 
 //---- RQ_OBJECT macro -----------------------------------------------
diff --git a/core/base/inc/Varargs.h b/core/base/inc/Varargs.h
index 2abae14d4837e..ca71b9f3a6797 100644
--- a/core/base/inc/Varargs.h
+++ b/core/base/inc/Varargs.h
@@ -11,6 +11,8 @@
 #ifndef ROOT_Varargs
 #define ROOT_Varargs
 
+#warning "The header Varargs.h is deprecated and will be removed in ROOT 6.46, include <cstdarg> instead."
+
 #if defined(sparc) && defined(__CC_ATT301__)
 
    extern "C" __builtin_va_arg_incr(...);
diff --git a/core/base/src/TErrorDefaultHandler.cxx b/core/base/src/TErrorDefaultHandler.cxx
index 8fa6c9e6419f8..1c64288a71e16 100644
--- a/core/base/src/TErrorDefaultHandler.cxx
+++ b/core/base/src/TErrorDefaultHandler.cxx
@@ -17,8 +17,8 @@
 #include <TError.h>
 #include <ThreadLocalStorage.h>
 #include <TSystem.h>
-#include <Varargs.h>
 
+#include <cstdarg>
 #include <cstdio>
 #include <cstdlib>
 #include <cctype> // for tolower
diff --git a/core/base/src/TObject.cxx b/core/base/src/TObject.cxx
index 8cf24354d95a7..fbd705f94056a 100644
--- a/core/base/src/TObject.cxx
+++ b/core/base/src/TObject.cxx
@@ -36,7 +36,6 @@ class hierarchies (watch out for overlaps).
    that the object was allocated on the heap).
 */
 
-#include "Varargs.h"
 #include "TObject.h"
 #include "TBuffer.h"
 #include "TClass.h"
@@ -55,13 +54,15 @@ class hierarchies (watch out for overlaps).
 #if !defined(WIN32) && !defined(__MWERKS__) && !defined(R__SOLARIS)
 #include <strings.h>
 #endif
+
+#include <cstdarg>
 #include <cstdlib>
 #include <cstdio>
-#include <sstream>
 #include <fstream>
-#include <iostream>
 #include <iomanip>
+#include <iostream>
 #include <limits>
+#include <sstream>
 
 Longptr_t TObject::fgDtorOnly   = 0;
 Bool_t    TObject::fgObjectStat = kTRUE;
@@ -1066,11 +1067,11 @@ void TObject::DoError(int level, const char *location, const char *fmt, va_list
 /// Issue info message. Use "location" to specify the method where the
 /// warning occurred. Accepts standard printf formatting arguments.
 
-void TObject::Info(const char *location, const char *va_(fmt), ...) const
+void TObject::Info(const char *location, const char *fmt, ...) const
 {
    va_list ap;
-   va_start(ap, va_(fmt));
-   DoError(kInfo, location, va_(fmt), ap);
+   va_start(ap, fmt);
+   DoError(kInfo, location, fmt, ap);
    va_end(ap);
 }
 
@@ -1078,11 +1079,11 @@ void TObject::Info(const char *location, const char *va_(fmt), ...) const
 /// Issue warning message. Use "location" to specify the method where the
 /// warning occurred. Accepts standard printf formatting arguments.
 
-void TObject::Warning(const char *location, const char *va_(fmt), ...) const
+void TObject::Warning(const char *location, const char *fmt, ...) const
 {
    va_list ap;
-   va_start(ap, va_(fmt));
-   DoError(kWarning, location, va_(fmt), ap);
+   va_start(ap, fmt);
+   DoError(kWarning, location, fmt, ap);
    va_end(ap);
    if (TROOT::Initialized())
       gROOT->Message(1001, this);
@@ -1092,11 +1093,11 @@ void TObject::Warning(const char *location, const char *va_(fmt), ...) const
 /// Issue error message. Use "location" to specify the method where the
 /// error occurred. Accepts standard printf formatting arguments.
 
-void TObject::Error(const char *location, const char *va_(fmt), ...) const
+void TObject::Error(const char *location, const char *fmt, ...) const
 {
    va_list ap;
-   va_start(ap, va_(fmt));
-   DoError(kError, location, va_(fmt), ap);
+   va_start(ap, fmt);
+   DoError(kError, location, fmt, ap);
    va_end(ap);
    if (TROOT::Initialized())
       gROOT->Message(1002, this);
@@ -1106,11 +1107,11 @@ void TObject::Error(const char *location, const char *va_(fmt), ...) const
 /// Issue system error message. Use "location" to specify the method where
 /// the system error occurred. Accepts standard printf formatting arguments.
 
-void TObject::SysError(const char *location, const char *va_(fmt), ...) const
+void TObject::SysError(const char *location, const char *fmt, ...) const
 {
    va_list ap;
-   va_start(ap, va_(fmt));
-   DoError(kSysError, location, va_(fmt), ap);
+   va_start(ap, fmt);
+   DoError(kSysError, location, fmt, ap);
    va_end(ap);
    if (TROOT::Initialized())
       gROOT->Message(1003, this);
@@ -1120,11 +1121,11 @@ void TObject::SysError(const char *location, const char *va_(fmt), ...) const
 /// Issue fatal error message. Use "location" to specify the method where the
 /// fatal error occurred. Accepts standard printf formatting arguments.
 
-void TObject::Fatal(const char *location, const char *va_(fmt), ...) const
+void TObject::Fatal(const char *location, const char *fmt, ...) const
 {
    va_list ap;
-   va_start(ap, va_(fmt));
-   DoError(kFatal, location, va_(fmt), ap);
+   va_start(ap, fmt);
+   DoError(kFatal, location, fmt, ap);
    va_end(ap);
    if (TROOT::Initialized())
       gROOT->Message(1004, this);
diff --git a/core/base/src/TString.cxx b/core/base/src/TString.cxx
index 6ff3cf6b3f258..0823444263b34 100644
--- a/core/base/src/TString.cxx
+++ b/core/base/src/TString.cxx
@@ -44,12 +44,7 @@ as a TString, construct a TString from it, eg:
 */
 
 #include <ROOT/RConfig.hxx>
-#include <cstdlib>
-#include <cctype>
-#include <list>
-#include <algorithm>
 
-#include "Varargs.h"
 #include "strlcpy.h"
 #include "TString.h"
 #include "TBuffer.h"
@@ -62,6 +57,12 @@ as a TString, construct a TString from it, eg:
 #include "TVirtualMutex.h"
 #include "ThreadLocalStorage.h"
 
+#include <cstdarg>
+#include <cstdlib>
+#include <cctype>
+#include <list>
+#include <algorithm>
+
 #if defined(R__WIN32)
 #define strtoull _strtoui64
 #endif
@@ -2390,7 +2391,7 @@ TObjArray *TString::Tokenize(const TString &delim) const
 void TString::FormImp(const char *fmt, va_list ap)
 {
    va_list ap_len;
-   R__VA_COPY(ap_len, ap);
+   va_copy(ap_len, ap);
 
    // First pass: determine required size (excluding '\0')
    int n = vsnprintf(nullptr, 0, fmt, ap_len);
@@ -2412,7 +2413,7 @@ void TString::FormImp(const char *fmt, va_list ap)
    }
 
    va_list ap_out;
-   R__VA_COPY(ap_out, ap);
+   va_copy(ap_out, ap);
    vsnprintf(GetPointer(), needed, fmt, ap_out);
    va_end(ap_out);
 
@@ -2434,11 +2435,11 @@ void TString::FormImp(const char *fmt, va_list ap)
 /// Note: this is not to be confused with ::Format and ::Form (in the global namespace)
 /// which returns a const char* and relies on a thread-local static character buffer.
 
-void TString::Form(const char *va_(fmt), ...)
+void TString::Form(const char *fmt, ...)
 {
    va_list ap;
-   va_start(ap, va_(fmt));
-   FormImp(va_(fmt), ap);
+   va_start(ap, fmt);
+   FormImp(fmt, ap);
    va_end(ap);
 }
 
@@ -2456,12 +2457,12 @@ void TString::Form(const char *va_(fmt), ...)
 /// Note: this is not to be confused with ::Format and ::Form (in the global namespace)
 /// which returns a const char* and relies on a thread-local static character buffer.
 
-TString TString::Format(const char *va_(fmt), ...)
+TString TString::Format(const char *fmt, ...)
 {
    va_list ap;
-   va_start(ap, va_(fmt));
+   va_start(ap, fmt);
    TString str;
-   str.FormImp(va_(fmt), ap);
+   str.FormImp(fmt, ap);
    va_end(ap);
    return str;
 }
@@ -2491,7 +2492,7 @@ static char *SlowFormat(const char *format, va_list ap, int hint)
    }
 
    va_list sap;
-   R__VA_COPY(sap, ap);
+   va_copy(sap, ap);
 
    int n = vsnprintf(slowBuffer, slowBufferSize, format, ap);
    // old vsnprintf's return -1 if string is truncated new ones return
@@ -2504,7 +2505,7 @@ static char *SlowFormat(const char *format, va_list ap, int hint)
          return nullptr; // int overflow!
       }
       va_end(ap);
-      R__VA_COPY(ap, sap);
+      va_copy(ap, sap);
       char *buf = SlowFormat(format, ap, n);
       va_end(sap);
       va_end(ap);
@@ -2540,14 +2541,14 @@ static char *Format(const char *format, va_list ap)
       buf = gFormbuf;
 
    va_list sap;
-   R__VA_COPY(sap, ap);
+   va_copy(sap, ap);
 
    int n = vsnprintf(buf, fld_size, format, ap);
    // old vsnprintf's return -1 if string is truncated new ones return
    // total number of characters that would have been written
    if (n == -1 || n >= fld_size) {
       va_end(ap);
-      R__VA_COPY(ap, sap);
+      va_copy(ap, sap);
       buf = SlowFormat(format, ap, n);
       va_end(sap);
       va_end(ap);
@@ -2567,11 +2568,11 @@ static char *Format(const char *format, va_list ap)
 /// be overwritten downstream. Use Form() results immediately or use
 /// TString::Format() instead.
 
-char *Form(const char *va_(fmt), ...)
+char *Form(const char *fmt, ...)
 {
    va_list ap;
-   va_start(ap,va_(fmt));
-   char *b = Format(va_(fmt), ap);
+   va_start(ap, fmt);
+   char *b = Format(fmt, ap);
    va_end(ap);
    return b;
 }
@@ -2581,14 +2582,14 @@ char *Form(const char *va_(fmt), ...)
 /// Appends a newline. If gPrintViaErrorHandler is true it will print via the
 /// currently active ROOT error handler.
 
-void Printf(const char *va_(fmt), ...)
+void Printf(const char *fmt, ...)
 {
    va_list ap;
-   va_start(ap,va_(fmt));
+   va_start(ap, fmt);
    if (gPrintViaErrorHandler)
-      ErrorHandler(kPrint, nullptr, va_(fmt), ap);
+      ErrorHandler(kPrint, nullptr, fmt, ap);
    else {
-      char *b = Format(va_(fmt), ap);
+      char *b = Format(fmt, ap);
       printf("%s\n", b);
       fflush(stdout);
    }
diff --git a/core/clingutils/res/TClingUtils.h b/core/clingutils/res/TClingUtils.h
index 3425e169446d6..3281c25b54104 100644
--- a/core/clingutils/res/TClingUtils.h
+++ b/core/clingutils/res/TClingUtils.h
@@ -20,7 +20,7 @@
 #include <list>
 #include <map>
 #include <utility>
-
+#include <cstdarg>
 #include <cstdlib>
 
 #if defined(__GNUC__) && !defined(__clang__)
@@ -87,8 +87,6 @@ namespace cling {
 // for TClassEdit::TInterpreterLookupHelper
 #include "TClassEdit.h"
 
-#include "Varargs.h"
-
 namespace ROOT {
 namespace TMetaUtils {
 
@@ -834,11 +832,11 @@ inline void LevelPrint(bool prefix, int level, const char *location, const char
 
    if (!location || !location[0]) {
       if (prefix) fprintf(stderr, "%s: ", type);
-      vfprintf(stderr, (const char*)va_(fmt), ap);
+      vfprintf(stderr, (const char *)fmt, ap);
    } else {
       if (prefix) fprintf(stderr, "%s in <%s>: ", type, location);
       else fprintf(stderr, "In <%s>: ", location);
-      vfprintf(stderr, (const char*)va_(fmt), ap);
+      vfprintf(stderr, (const char *)fmt, ap);
    }
 
    fflush(stderr);
@@ -851,51 +849,51 @@ inline void LevelPrint(bool prefix, int level, const char *location, const char
 
 //______________________________________________________________________________
 // Use this function in case an error occurred.
-inline void Error(const char *location, const char *va_(fmt), ...)
+inline void Error(const char *location, const char *fmt, ...)
 {
    va_list ap;
-   va_start(ap,va_(fmt));
-   LevelPrint(true, ROOT::TMetaUtils::kError, location, va_(fmt), ap);
+   va_start(ap, fmt);
+   LevelPrint(true, ROOT::TMetaUtils::kError, location, fmt, ap);
    va_end(ap);
 }
 
 //______________________________________________________________________________
 // Use this function in case a system (OS or GUI) related error occurred.
-inline void SysError(const char *location, const char *va_(fmt), ...)
+inline void SysError(const char *location, const char *fmt, ...)
 {
    va_list ap;
-   va_start(ap, va_(fmt));
-   LevelPrint(true, ROOT::TMetaUtils::kSysError, location, va_(fmt), ap);
+   va_start(ap, fmt);
+   LevelPrint(true, ROOT::TMetaUtils::kSysError, location, fmt, ap);
    va_end(ap);
 }
 
 //______________________________________________________________________________
 // Use this function for informational messages.
-inline void Info(const char *location, const char *va_(fmt), ...)
+inline void Info(const char *location, const char *fmt, ...)
 {
    va_list ap;
-   va_start(ap,va_(fmt));
-   LevelPrint(true, ROOT::TMetaUtils::kInfo, location, va_(fmt), ap);
+   va_start(ap, fmt);
+   LevelPrint(true, ROOT::TMetaUtils::kInfo, location, fmt, ap);
    va_end(ap);
 }
 
 //______________________________________________________________________________
 // Use this function in warning situations.
-inline void Warning(const char *location, const char *va_(fmt), ...)
+inline void Warning(const char *location, const char *fmt, ...)
 {
    va_list ap;
-   va_start(ap,va_(fmt));
-   LevelPrint(true, ROOT::TMetaUtils::kWarning, location, va_(fmt), ap);
+   va_start(ap, fmt);
+   LevelPrint(true, ROOT::TMetaUtils::kWarning, location, fmt, ap);
    va_end(ap);
 }
 
 //______________________________________________________________________________
 // Use this function in case of a fatal error. It will abort the program.
-inline void Fatal(const char *location, const char *va_(fmt), ...)
+inline void Fatal(const char *location, const char *fmt, ...)
 {
    va_list ap;
-   va_start(ap,va_(fmt));
-   LevelPrint(true, ROOT::TMetaUtils::kFatal, location, va_(fmt), ap);
+   va_start(ap, fmt);
+   LevelPrint(true, ROOT::TMetaUtils::kFatal, location, fmt, ap);
    va_end(ap);
 }
 
diff --git a/core/clingutils/src/RStl.cxx b/core/clingutils/src/RStl.cxx
index 7baad1ee29030..73c8be3e717f6 100644
--- a/core/clingutils/src/RStl.cxx
+++ b/core/clingutils/src/RStl.cxx
@@ -15,9 +15,6 @@
 #include "RStl.h"
 #include "TClassEdit.h"
 #include "TClingUtils.h"
-using namespace TClassEdit;
-
-#include <cstdio>
 
 #include "clang/AST/Decl.h"
 #include "clang/AST/DeclTemplate.h"
@@ -29,7 +26,10 @@ using namespace TClassEdit;
 #include "clang/Sema/Template.h"
 #include "clang/Frontend/CompilerInstance.h"
 
-#include "Varargs.h"
+#include <cstdarg>
+#include <cstdio>
+
+using namespace TClassEdit;
 
 //
 // ROOT::Internal::RStl is the rootcint STL handling class.
diff --git a/core/cont/src/TCollection.cxx b/core/cont/src/TCollection.cxx
index 81fe664eea6fb..e4032089a3503 100644
--- a/core/cont/src/TCollection.cxx
+++ b/core/cont/src/TCollection.cxx
@@ -63,7 +63,6 @@ for (auto br : TRangeDynCast<TBranch>( tree->GetListOfBranches() )) {
 */
 
 #include "TCollection.h"
-#include "Varargs.h"
 #include "TBuffer.h"
 #include "TClass.h"
 #include "TROOT.h"
@@ -77,6 +76,7 @@ for (auto br : TRangeDynCast<TBranch>( tree->GetListOfBranches() )) {
 #include "TObjArray.h"
 #include "TMathBase.h"
 
+#include <cstdarg>
 #include <iostream>
 #include <sstream>
 
@@ -236,13 +236,13 @@ void TCollection::AddAll(const TCollection *col)
 /// Add all arguments to the collection. The list of objects must be
 /// terminated by 0, e.g.: l.AddVector(o1, o2, o3, o4, 0);
 
-void TCollection::AddVector(TObject *va_(obj1), ...)
+void TCollection::AddVector(TObject *obj1, ...)
 {
    va_list ap;
-   va_start(ap, va_(obj1));
+   va_start(ap, obj1);
    TObject *obj;
 
-   Add(va_(obj1));
+   Add(obj1);
    while ((obj = va_arg(ap, TObject *)))
       Add(obj);
    va_end(ap);
diff --git a/core/thread/src/TThread.cxx b/core/thread/src/TThread.cxx
index 7d7766cb0be6e..a27b200d421b0 100644
--- a/core/thread/src/TThread.cxx
+++ b/core/thread/src/TThread.cxx
@@ -35,13 +35,14 @@ TPosixThread or TWin32Thread).
 #include "TInterpreter.h"
 #include "TError.h"
 #include "TSystem.h"
-#include "Varargs.h"
 #include "ThreadLocalStorage.h"
 #include "TThreadSlots.h"
 #include "TRWMutexImp.h"
 
 #include <cstdio>
 
+#include <cstdarg>
+
 TThreadImp     *TThread::fgThreadImp = nullptr;
 Long_t          TThread::fgMainId = 0;
 TThread        *TThread::fgMain = nullptr;
@@ -917,10 +918,10 @@ void **TThread::GetTls(Int_t k) {
 ////////////////////////////////////////////////////////////////////////////////
 /// Static method providing a thread safe printf. Appends a newline.
 
-void TThread::Printf(const char *va_(fmt), ...)
+void TThread::Printf(const char *fmt, ...)
 {
    va_list ap;
-   va_start(ap,va_(fmt));
+   va_start(ap, fmt);
 
    Int_t buf_size = 2048;
    char *buf;
@@ -928,7 +929,7 @@ void TThread::Printf(const char *va_(fmt), ...)
 again:
    buf = new char[buf_size];
 
-   int n = vsnprintf(buf, buf_size, va_(fmt), ap);
+   int n = vsnprintf(buf, buf_size, fmt, ap);
    // old vsnprintf's return -1 if string is truncated new ones return
    // total number of characters that would have been written
    if (n == -1 || n >= buf_size) {
diff --git a/gui/gui/src/TRootBrowser.cxx b/gui/gui/src/TRootBrowser.cxx
index e85ba54768025..029dc078bff22 100644
--- a/gui/gui/src/TRootBrowser.cxx
+++ b/gui/gui/src/TRootBrowser.cxx
@@ -74,7 +74,6 @@ Here is the list of available options:
 #include "TGLayout.h"
 #include "TGSplitter.h"
 #include "TGStatusBar.h"
-#include "Varargs.h"
 #include "TInterpreter.h"
 #include "TGFileDialog.h"
 #include "TObjString.h"
@@ -96,6 +95,8 @@ Here is the list of available options:
 
 #include <cstdio>
 
+#include <cstdarg>
+
 #ifdef WIN32
 #include <TWin32SplashThread.h>
 #endif
diff --git a/io/xmlparser/src/TSAXParser.cxx b/io/xmlparser/src/TSAXParser.cxx
index 0c51ad067e073..348cf72e10370 100644
--- a/io/xmlparser/src/TSAXParser.cxx
+++ b/io/xmlparser/src/TSAXParser.cxx
@@ -35,7 +35,6 @@ occur.
 
 #include "TSAXParser.h"
 #include "TXMLAttr.h"
-#include "Varargs.h"
 #include "strlcpy.h"
 #include "TList.h"
 #include "TClass.h"
@@ -43,6 +42,7 @@ occur.
 #include <libxml/parser.h>
 #include <libxml/parserInternals.h>
 
+#include <cstdarg>
 
 class TSAXParserCallback {
 public:
@@ -352,15 +352,15 @@ void TSAXParserCallback::Comment(void *fParser, const xmlChar *value)
 /// Warning callback function. Warnings while parsing a xml file will
 /// be stored at fmt.
 
-void TSAXParserCallback::Warning(void * fParser, const char *va_(fmt), ...)
+void TSAXParserCallback::Warning(void *fParser, const char *fmt, ...)
 {
    TSAXParser *parser = (TSAXParser*)fParser;
 
    va_list arg;
    char buffer[2048];
 
-   va_start(arg, va_(fmt));
-   vsnprintf(buffer, 2048, va_(fmt), arg);
+   va_start(arg, fmt);
+   vsnprintf(buffer, 2048, fmt, arg);
    va_end(arg);
 
    TString buff(buffer);
@@ -372,7 +372,7 @@ void TSAXParserCallback::Warning(void * fParser, const char *va_(fmt), ...)
 /// Error callback function. Errors while parsing a xml file will be stored
 /// at fmt.
 
-void TSAXParserCallback::Error(void *fParser, const char *va_(fmt), ...)
+void TSAXParserCallback::Error(void *fParser, const char *fmt, ...)
 {
    Int_t errorcode;
    TSAXParser *parser = (TSAXParser*)fParser;
@@ -380,8 +380,8 @@ void TSAXParserCallback::Error(void *fParser, const char *va_(fmt), ...)
    va_list arg;
    char buffer[2048];
 
-   va_start(arg, va_(fmt));
-   vsnprintf(buffer, 2048, va_(fmt), arg);
+   va_start(arg, fmt);
+   vsnprintf(buffer, 2048, fmt, arg);
    va_end(arg);
 
    TString buff(buffer);
@@ -401,7 +401,7 @@ void TSAXParserCallback::Error(void *fParser, const char *va_(fmt), ...)
 /// FactalError callback function. Factal errors while parsing a xml file
 /// will be stored at fmt.
 
-void TSAXParserCallback::FatalError(void *fParser, const char *va_(fmt), ...)
+void TSAXParserCallback::FatalError(void *fParser, const char *fmt, ...)
 {
    Int_t errorcode;
    TSAXParser *parser = (TSAXParser*)fParser;
@@ -409,8 +409,8 @@ void TSAXParserCallback::FatalError(void *fParser, const char *va_(fmt), ...)
    va_list arg;
    char buffer[2048];
 
-   va_start(arg, va_(fmt));
-   vsnprintf(buffer, 2048, va_(fmt), arg);
+   va_start(arg, fmt);
+   vsnprintf(buffer, 2048, fmt, arg);
    va_end(arg);
 
    TString buff(buffer);
diff --git a/math/matrix/src/TVectorT.cxx b/math/matrix/src/TVectorT.cxx
index bb197eb35a777..6d0033ae242c4 100644
--- a/math/matrix/src/TVectorT.cxx
+++ b/math/matrix/src/TVectorT.cxx
@@ -41,8 +41,8 @@ For usage examples see `$ROOTSYS/test/stressLinear.cxx`
 #include "TBuffer.h"
 #include "TMath.h"
 #include "TROOT.h"
-#include "Varargs.h"
 
+#include <cstdarg>
 #include <type_traits>
 
 
diff --git a/tree/treeplayer/src/TTreeProxyGenerator.cxx b/tree/treeplayer/src/TTreeProxyGenerator.cxx
index 041ce03261c3f..72575b5446eeb 100644
--- a/tree/treeplayer/src/TTreeProxyGenerator.cxx
+++ b/tree/treeplayer/src/TTreeProxyGenerator.cxx
@@ -46,8 +46,6 @@
 #include "TBranchProxyClassDescriptor.h"
 
 #include "TList.h"
-#include "Varargs.h"
-#include <cstdio>
 
 class TTree;
 class TBranch;
@@ -76,14 +74,17 @@ class TStreamerElement;
 #include "TLeafObject.h"
 #include "TVirtualCollectionProxy.h"
 
-void Debug(Int_t level, const char *va_(fmt), ...)
+#include <cstdarg>
+#include <cstdio>
+
+void Debug(Int_t level, const char *fmt, ...)
 {
    // Use this function in case an error occurred.
 
    if (gDebug>=level) {
       va_list ap;
-      va_start(ap,va_(fmt));
-      ErrorHandler(kInfo,"TTreeProxyGenerator",va_(fmt), ap);
+      va_start(ap, fmt);
+      ErrorHandler(kInfo, "TTreeProxyGenerator", fmt, ap);
       va_end(ap);
    }
 }