diff --git a/Doc/whatsnew/3.8.rst b/Doc/whatsnew/3.8.rst
index 684656f..ac25305 100644
--- a/Doc/whatsnew/3.8.rst
+++ b/Doc/whatsnew/3.8.rst
@@ -990,6 +990,11 @@
 Changes in the C API
 --------------------
 
+* The :c:func:`PyEval_ReInitThreads` function has been removed from the C API.
+  It should not be called explicitly: use :c:func:`PyOS_AfterFork_Child`
+  instead.
+  (Contributed by Victor Stinner in :issue:`36728`.)
+
 * On Unix, C extensions are no longer linked to libpython except on
   Android. When Python is embedded, ``libpython`` must not be loaded with
   ``RTLD_LOCAL``, but ``RTLD_GLOBAL`` instead. Previously, using
diff --git a/Include/ceval.h b/Include/ceval.h
index 2d4b67d..8cdf353 100644
--- a/Include/ceval.h
+++ b/Include/ceval.h
@@ -195,7 +195,6 @@
 PyAPI_FUNC(void) PyEval_ReleaseLock(void) /* Py_DEPRECATED(3.2) */;
 PyAPI_FUNC(void) PyEval_AcquireThread(PyThreadState *tstate);
 PyAPI_FUNC(void) PyEval_ReleaseThread(PyThreadState *tstate);
-PyAPI_FUNC(void) PyEval_ReInitThreads(void);
 
 #ifndef Py_LIMITED_API
 PyAPI_FUNC(void) _PyEval_SetSwitchInterval(unsigned long microseconds);
diff --git a/Include/internal/pycore_ceval.h b/Include/internal/pycore_ceval.h
index cdc73a3..7a3166e 100644
--- a/Include/internal/pycore_ceval.h
+++ b/Include/internal/pycore_ceval.h
@@ -24,6 +24,8 @@
     void *arg);
 PyAPI_FUNC(void) _PyEval_SignalAsyncExc(
     struct _ceval_runtime_state *ceval);
+PyAPI_FUNC(void) _PyEval_ReInitThreads(
+    _PyRuntimeState *runtime);
 
 #ifdef __cplusplus
 }
diff --git a/Misc/NEWS.d/next/C API/2019-05-11-03-56-23.bpo-36728.FR-dMP.rst b/Misc/NEWS.d/next/C API/2019-05-11-03-56-23.bpo-36728.FR-dMP.rst
new file mode 100644
index 0000000..c691cc4
--- /dev/null
+++ b/Misc/NEWS.d/next/C API/2019-05-11-03-56-23.bpo-36728.FR-dMP.rst
@@ -0,0 +1,2 @@
+The :c:func:`PyEval_ReInitThreads` function has been removed from the C API.
+It should not be called explicitly: use :c:func:`PyOS_AfterFork_Child` instead.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index aa77094..aca64ef 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -25,14 +25,25 @@
 #define PY_SSIZE_T_CLEAN
 
 #include "Python.h"
+#ifdef MS_WINDOWS
+   /* include <windows.h> early to avoid conflict with pycore_condvar.h:
+
+        #define WIN32_LEAN_AND_MEAN
+        #include <windows.h>
+
+      FSCTL_GET_REPARSE_POINT is not exported with WIN32_LEAN_AND_MEAN. */
+#  include <windows.h>
+#endif
+
+#include "pycore_ceval.h"     /* _PyEval_ReInitThreads() */
+#include "pycore_pystate.h"   /* _PyRuntime */
 #include "pythread.h"
 #include "structmember.h"
 #ifndef MS_WINDOWS
-#include "posixmodule.h"
+#  include "posixmodule.h"
 #else
-#include "winreparse.h"
+#  include "winreparse.h"
 #endif
-#include "pycore_pystate.h"
 
 /* On android API level 21, 'AT_EACCESS' is not declared although
  * HAVE_FACCESSAT is defined. */
@@ -424,7 +435,7 @@
     _PyRuntimeState *runtime = &_PyRuntime;
     _PyGILState_Reinit(runtime);
     _PyInterpreterState_DeleteExceptMain(runtime);
-    PyEval_ReInitThreads();
+    _PyEval_ReInitThreads(runtime);
     _PyImport_ReInitLock();
     _PySignal_AfterFork();
     _PyRuntimeState_ReInitThreads(runtime);
diff --git a/Python/ceval.c b/Python/ceval.c
index 1743953..1bb4704 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -289,9 +289,8 @@
  */
 
 void
-PyEval_ReInitThreads(void)
+_PyEval_ReInitThreads(_PyRuntimeState *runtime)
 {
-    _PyRuntimeState *runtime = &_PyRuntime;
     struct _ceval_runtime_state *ceval = &runtime->ceval;
     if (!gil_created(&ceval->gil)) {
         return;