diff --git a/ChangeLog b/ChangeLog
index 9b04d5f68f..559c6b7840 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Nov 24 15:18:07 2010  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* vsnprintf (BSD_vfprintf): use QUADINT macro only when _HAVE_SANE_QUAD_
+	  macro is defined.
+
 Wed Nov 24 12:47:16 2010  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* vsnprintf (BSD_vfprintf): added VC++ compatible size specifications
diff --git a/vsnprintf.c b/vsnprintf.c
index a68b0d05dc..196e733985 100644
--- a/vsnprintf.c
+++ b/vsnprintf.c
@@ -764,12 +764,14 @@ reswitch:	switch (ch) {
 			    fmt += 2;
 			    flags |= LONGINT;
 			}
+#ifdef _HAVE_SANE_QUAD_
 			else if (*fmt == '6' && *(fmt + 1) == '4') {
 			    fmt += 2;
 			    flags |= QUADINT;
 			}
+#endif
 			else
-#if SIZEOF_SIZE_T == SIZEOF_LONG_LONG
+#if defined(_HAVE_SANE_QUAD_) && SIZEOF_SIZE_T == SIZEOF_LONG_LONG
 			    flags |= QUADINT;
 #else
 			    flags |= LONGINT;