diff --git a/ChangeLog b/ChangeLog
index 96bc386f86..b62f9bf978 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Fri Dec 10 10:47:53 2010  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* sprintf.c (_HAVE_SANE_QUAD_): Don't forget LP64, r30156.
+
 Fri Dec 10 10:37:17 2010  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* sprintf.c (_HAVE_SANE_QUAD_): if a certain platform has LONG_LONG in
diff --git a/sprintf.c b/sprintf.c
index 25633e0490..07bd740237 100644
--- a/sprintf.c
+++ b/sprintf.c
@@ -1121,10 +1121,10 @@ fmt_setup(char *buf, size_t size, int c, int flags, int width, int prec)
 #  define quad_t LONG_LONG
 #  define u_quad_t unsigned LONG_LONG
 # endif
-#elif  SIZEOF_LONG_LONG == 8
-#  define _HAVE_SANE_QUAD_
-#  define quad_t LONG_LONG
-#  define u_quad_t unsigned LONG_LONG
+#elif SIZEOF_LONG != SIZEOF_LONG_LONG && SIZEOF_LONG_LONG == 8
+# define _HAVE_SANE_QUAD_
+# define quad_t LONG_LONG
+# define u_quad_t unsigned LONG_LONG
 #endif
 #define FLOATING_POINT 1
 #define BSD__dtoa ruby_dtoa