diff --git a/src/kernel/libroot/posix/stdlib/exit.c b/src/kernel/libroot/posix/stdlib/exit.c
index d6eb2b06ec..1dab60e976 100644
--- a/src/kernel/libroot/posix/stdlib/exit.c
+++ b/src/kernel/libroot/posix/stdlib/exit.c
@@ -14,21 +14,20 @@
  *
  */
 
+
 #include <syscalls.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <signal.h>
 #include <limits.h>
 
-// ToDo: move this puppy to a more standard location
 #include "../stdio/local.h"
+//#include "stdio_private.h"
 
 extern void _thread_do_exit_notification(void);
 
-
-static void (*_Exit_Stack[ATEXIT_MAX])(void) = {0};
-static int    _Exit_SP = 0;
-
+static void (*_gExitStack[ATEXIT_MAX])(void) = {0};
+static int32 _gExitStackIndex = 0;
 
 
 void
@@ -43,13 +42,13 @@ int
 atexit(void (*func)(void))
 {
 	// push the function pointer onto the exit stack
-	
-	if (_Exit_SP < ATEXIT_MAX) {
-		_Exit_Stack[_Exit_SP++] = func;
-		return 0;
-	}
-	
-	return -1;
+	int32 index = atomic_add(&_gExitStackIndex, 1);
+
+	if (index >= ATEXIT_MAX)
+		return -1;
+
+	_gExitStack[index] = func;
+	return 0;
 }
 
 
@@ -60,12 +59,13 @@ exit(int status)
 	_thread_do_exit_notification();
 
 	// unwind the exit stack, calling the registered functions
-	while (_Exit_SP > 0)
-		(*_Exit_Stack[--_Exit_SP])();
-	
+	while (_gExitStackIndex-- > 0)
+		(*_gExitStack[_gExitStackIndex])();
+
 	// close all open files
-	(*__cleanup)();
-	
+	_IO_cleanup();
+
 	// exit with status code
 	sys_exit(status);
 }
+