diff --git a/ChangeLog b/ChangeLog
index aef7f703b1..3bde0aee60 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sat Jan  9 14:01:14 2010  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* missing/vsnprintf.c (BSD_vfprintf): get rid of a warning of VC++ x64.
+
 Sat Jan  9 08:40:54 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* win32/configure.bat (WIN32DIR): regularise file separators.
diff --git a/missing/vsnprintf.c b/missing/vsnprintf.c
index 5718362fed..4e19651679 100644
--- a/missing/vsnprintf.c
+++ b/missing/vsnprintf.c
@@ -769,7 +769,7 @@ reswitch:	switch (ch) {
 			if (flags & QUADINT) {
 				uqval = va_arg(ap, quad_t);
 				if ((quad_t)uqval < 0) {
-					uqval = -uqval;
+					uqval = -(quad_t)uqval;
 					sign = '-';
 				}
 			} else