diff --git a/ChangeLog b/ChangeLog
index 06c9daf03d7e6f..5dc45a0c25d5e1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Mon Jul  8 23:12:22 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* thread_win32.c (w32_thread_start_func, thread_start_func_1),
+	  (timer_thread_func): use __stdcall instead of _stdcall which is
+	  unavailable in strict ANSI mode.  [ruby-core:55312] [Bug #8495]
+
+	* win32/win32.c (gettimeofday): use __cdecl instead of _cdecl.
+
 Mon Jul  8 22:41:12 2013  Tanaka Akira  <akr@fsij.org>
 
 	* bignum.c (bary_mul): Arguments for work memory added.
diff --git a/thread_win32.c b/thread_win32.c
index 0128f6323c7c15..86f3e3c41eefd2 100644
--- a/thread_win32.c
+++ b/thread_win32.c
@@ -269,7 +269,7 @@ w32_resume_thread(HANDLE handle)
 #ifdef HAVE__BEGINTHREADEX
 #define start_thread (HANDLE)_beginthreadex
 #define thread_errno errno
-typedef unsigned long (_stdcall *w32_thread_start_func)(void*);
+typedef unsigned long (__stdcall *w32_thread_start_func)(void*);
 #else
 #define start_thread CreateThread
 #define thread_errno rb_w32_map_errno(GetLastError())
@@ -587,7 +587,7 @@ native_thread_destroy(rb_thread_t *th)
     w32_close_handle(intr);
 }
 
-static unsigned long _stdcall
+static unsigned long __stdcall
 thread_start_func_1(void *th_ptr)
 {
     rb_thread_t *th = th_ptr;
@@ -695,7 +695,7 @@ ubf_handle(void *ptr)
 static HANDLE timer_thread_id = 0;
 static HANDLE timer_thread_lock;
 
-static unsigned long _stdcall
+static unsigned long __stdcall
 timer_thread_func(void *dummy)
 {
     thread_debug("timer_thread\n");
diff --git a/win32/win32.c b/win32/win32.c
index 6c27ffa2775aa9..c7ee9844b17f02 100644
--- a/win32/win32.c
+++ b/win32/win32.c
@@ -4274,7 +4274,7 @@ filetime_to_timeval(const FILETIME* ft, struct timeval *tv)
 }
 
 /* License: Ruby's */
-int _cdecl
+int __cdecl
 gettimeofday(struct timeval *tv, struct timezone *tz)
 {
     FILETIME ft;