diff --git a/ChangeLog b/ChangeLog
index 141b8be153..f767fc5de1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue May 26 21:09:21 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* win32/win32.c (_CrtDbgReportW): prevent from false positive
+	  assertions in msvcrtd.  [ruby-core:22116]
+
 Tue May 26 21:02:13 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/ostruct.rb (OpenStruct#new_ostruct_member): checks if frozen.
diff --git a/version.h b/version.h
index 58ca2fe4be..cf257954e0 100644
--- a/version.h
+++ b/version.h
@@ -2,7 +2,7 @@
 #define RUBY_RELEASE_DATE "2009-05-26"
 #define RUBY_VERSION_CODE 187
 #define RUBY_RELEASE_CODE 20090526
-#define RUBY_PATCHLEVEL 163
+#define RUBY_PATCHLEVEL 164
 
 #define RUBY_VERSION_MAJOR 1
 #define RUBY_VERSION_MINOR 8
diff --git a/win32/Makefile.sub b/win32/Makefile.sub
index 1301d86fff..c2e09abd42 100644
--- a/win32/Makefile.sub
+++ b/win32/Makefile.sub
@@ -172,12 +172,12 @@ LDSHARED = $(LD) -LD
 XCFLAGS = -DRUBY_EXPORT -I. -I$(srcdir) -I$(srcdir)/missing $(XCFLAGS)
 !if $(MSC_VER) >= 1400
 # Prevents VC++ 2005 (cl ver 14) warnings
-DEFS = -D_CRT_SECURE_NO_DEPRECATE -D_CRT_NONSTDC_NO_DEPRECATE
+CRTDEFFLAGS = -D_CRT_SECURE_NO_DEPRECATE -D_CRT_NONSTDC_NO_DEPRECATE
 MANIFESTTOOL = mt -nologo
 LDSHARED_1 = $(MANIFESTTOOL) -manifest $(@).manifest -outputresource:$(@);2
 LDSHARED_2 = @$(RM) $(@:/=\).manifest
 !endif
-CPPFLAGS = $(DEFS) $(ARCHDEFS) $(CPPFLAGS)
+CPPFLAGS = $(CRTDEFFLAGS) $(DEFS) $(ARCHDEFS) $(CPPFLAGS)
 
 DLDFLAGS = $(LDFLAGS) -dll
 SOLIBS = 
@@ -321,6 +321,10 @@ $(CONFIG_H): $(MKFILES) $(srcdir)/win32/Makefile.sub $(win_srcdir)/Makefile.sub
 !if $(MSC_VER) > 1100
 #define NORETURN(x) __declspec(noreturn) x
 !endif
+!if $(MSC_VER) >= 1300
+#define DEPRECATED(x) __declspec(deprecated) x
+#define NOINLINE(x) __declspec(noinline) x
+!endif
 #define RUBY_EXTERN extern __declspec(dllimport)
 #define HAVE_DECL_SYS_NERR 1
 !if !defined(WIN32_WCE)
diff --git a/win32/win32.c b/win32/win32.c
index 1d342316fe..165cdc6b29 100644
--- a/win32/win32.c
+++ b/win32/win32.c
@@ -27,6 +27,9 @@
 #include <winbase.h>
 #include <wincon.h>
 #include <shlobj.h>
+#if _MSC_VER >= 1400
+#include <crtdbg.h>
+#endif
 #ifdef __MINGW32__
 #include <mswsock.h>
 #include <mbstring.h>
@@ -366,10 +369,17 @@ flock(int fd, int oper)
 static void init_stdhandle(void);
 
 #if _MSC_VER >= 1400
-static void invalid_parameter(const wchar_t *expr, const wchar_t *func, const wchar_t *file, unsigned int line, uintptr_t dummy)
+static void
+invalid_parameter(const wchar_t *expr, const wchar_t *func, const wchar_t *file, unsigned int line, uintptr_t dummy)
 {
     // nothing to do
 }
+
+static int __cdecl
+rtc_error_handler(int e, const char *src, int line, const char *exe, const char *fmt, ...)
+{
+    return 0;
+}
 #endif
 
 static CRITICAL_SECTION select_mutex;
@@ -452,7 +462,9 @@ NtInitialize(int *argc, char ***argv)
 #if _MSC_VER >= 1400
     static void set_pioinfo_extra(void);
 
+    _CrtSetReportMode(_CRT_ASSERT, 0);
     _set_invalid_parameter_handler(invalid_parameter);
+    _RTC_SetErrorFunc(rtc_error_handler);
     set_pioinfo_extra();
 #endif
 
@@ -4199,3 +4211,5 @@ rb_w32_fsopen(const char *path, const char *mode, int shflags)
     return f;
 }
 #endif
+
+RUBY_EXTERN int __cdecl _CrtDbgReportW() {return 0;}