diff --git a/README/ReleaseNotes/v642/index.md b/README/ReleaseNotes/v642/index.md
index 317fa53b195d1..005e7acade3d8 100644
--- a/README/ReleaseNotes/v642/index.md
+++ b/README/ReleaseNotes/v642/index.md
@@ -73,6 +73,7 @@ The `TMVA_SOFIE_GNN` tutorials have been migrated to this workflow and produce i
 * The header `Rpair.h` is deprecated and will be removed after ROOT 6.44.
 * The headers `Htypes.h` and `Gtypes.h` that were deprecated in ROOT 6.20 will now emit warnings and will be fully removed in ROOT 6.44. Use instead `Rtypes.h`.
 * The header `GLConstants.h` is no longer part of ROOT installed headers.
+* The header `PosixThreadInc.h` is deprecated and will be removed after ROOT 6.44. Use instead `<ctime>` and `<cstdlib>`.
 * 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.
diff --git a/core/thread/CMakeLists.txt b/core/thread/CMakeLists.txt
index 83133efce59a4..66e0540881cdb 100644
--- a/core/thread/CMakeLists.txt
+++ b/core/thread/CMakeLists.txt
@@ -23,7 +23,6 @@ else()
     TPosixMutex.h
     TPosixThread.h
     TPosixThreadFactory.h
-    PosixThreadInc.h
   )
 endif()
 
diff --git a/core/thread/inc/PosixThreadInc.h b/core/thread/inc/PosixThreadInc.h
index 1f3c8b2c42ca9..209120a611abc 100644
--- a/core/thread/inc/PosixThreadInc.h
+++ b/core/thread/inc/PosixThreadInc.h
@@ -11,6 +11,7 @@
 #ifndef ROOT_PosixThreadInc
 #define ROOT_PosixThreadInc
 
+#warning "This header is deprecated and will be removed after ROOT 6.44, use instead <cstdlib> and <ctime>"
 
 //////////////////////////////////////////////////////////////////////////
 //                                                                      //
diff --git a/core/thread/src/TPosixCondition.cxx b/core/thread/src/TPosixCondition.cxx
index a0ba18e0f9917..9fc7c9cc41799 100644
--- a/core/thread/src/TPosixCondition.cxx
+++ b/core/thread/src/TPosixCondition.cxx
@@ -20,8 +20,8 @@
 
 #include "TPosixCondition.h"
 #include "TPosixMutex.h"
-#include "PosixThreadInc.h"
 
+#include <ctime>
 #include <cerrno>
 
 
diff --git a/core/thread/src/TPosixMutex.cxx b/core/thread/src/TPosixMutex.cxx
index a3c58217322d6..8e315be14dac6 100644
--- a/core/thread/src/TPosixMutex.cxx
+++ b/core/thread/src/TPosixMutex.cxx
@@ -17,10 +17,7 @@
 //                                                                      //
 //////////////////////////////////////////////////////////////////////////
 
-#include "TThread.h"
 #include "TPosixMutex.h"
-#include "PosixThreadInc.h"
-
 
 ////////////////////////////////////////////////////////////////////////////////
 /// Create a posix mutex lock.