diff --git a/ChangeLog b/ChangeLog
index 79d702b309..09864367ce 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Apr 28 10:27:33 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* vsnprintf.c (ruby_vsnprintf, ruby_snprintf): suppress warnings.
+	  why return int in spite of the arguments of size_t?
+
 Wed Apr 28 09:49:21 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* tool/compile_prelude.rb: enable optimization.
diff --git a/vsnprintf.c b/vsnprintf.c
index 6385aa1aa7..a389d15fc3 100644
--- a/vsnprintf.c
+++ b/vsnprintf.c
@@ -1229,7 +1229,7 @@ ruby_vsnprintf(char *str, size_t n, const char *fmt, va_list ap)
 	f._bf._base = f._p = (unsigned char *)str;
 	f._bf._size = f._w = n - 1;
 	f.vwrite = BSD__sfvwrite;
-	ret = BSD_vfprintf(&f, fmt, ap);
+	ret = (int)BSD_vfprintf(&f, fmt, ap);
 	*f._p = 0;
 	return (ret);
 }
@@ -1249,7 +1249,7 @@ ruby_snprintf(char *str, size_t n, char const *fmt, ...)
 	f._bf._base = f._p = (unsigned char *)str;
 	f._bf._size = f._w = n - 1;
 	f.vwrite = BSD__sfvwrite;
-	ret = BSD_vfprintf(&f, fmt, ap);
+	ret = (int)BSD_vfprintf(&f, fmt, ap);
 	*f._p = 0;
 	va_end(ap);
 	return (ret);