diff --git a/Misc/ACKS b/Misc/ACKS
index 7d4c1bf..8ca5b7f 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -689,6 +689,7 @@
 Nathan Sullivan
 Mark Summerfield
 Hisao Suzuki
+Andrew Svetlov
 Kalle Svensson
 Andrew Svetlov
 Paul Swartz
diff --git a/Misc/NEWS b/Misc/NEWS
index a52e37a..916a2c9 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -53,6 +53,9 @@
 Library
 -------
 
+- Issue #5619: Multiprocessing children disobey the debug flag and causes
+  popups on windows buildbots. Patch applied to work around this issue.
+
 - Issue #5400: Added patch for multiprocessing on netbsd compilation/support
 
 - Issue #5387: Fixed mmap.move crash by integer overflow.
diff --git a/Modules/_multiprocessing/win32_functions.c b/Modules/_multiprocessing/win32_functions.c
index 379a495..ba82c23 100644
--- a/Modules/_multiprocessing/win32_functions.c
+++ b/Modules/_multiprocessing/win32_functions.c
@@ -130,6 +130,12 @@
 	if (!PyArg_ParseTuple(args, "I", &uExitCode))
 		return NULL;
 
+	#if defined(Py_DEBUG)
+		SetErrorMode(SEM_FAILCRITICALERRORS|SEM_NOALIGNMENTFAULTEXCEPT|SEM_NOGPFAULTERRORBOX|SEM_NOOPENFILEERRORBOX);
+		_CrtSetReportMode(_CRT_ASSERT, _CRTDBG_MODE_DEBUG);
+	#endif
+
+
 	ExitProcess(uExitCode);
 
 	return NULL;
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 7add832..27c9d23 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -2006,6 +2006,7 @@
 Py_FatalError(const char *msg)
 {
 	fprintf(stderr, "Fatal Python error: %s\n", msg);
+	fflush(stderr); /* it helps in Windows debug build */
 	if (PyErr_Occurred()) {
 		PyErr_Print();
 	}