diff --git a/ChangeLog b/ChangeLog
index 95a6c3cc56..95b620e1ae 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Wed Oct 26 09:04:51 2005  Hirokazu Yamamoto  <ocean@m2.ccsnet.ne.jp>
+
+	* ruby.h (Qfalse, Qtrue, Qnil, Qundef): make sure these immediate
+	  values have VALUE type. there is an environment where sizeof(VALUE)
+	  != sizeof(int) like IA64. if 32bit integer (Qtrue) is passed to ANYARGS
+	  and received by 64bit integer (VALUE), upper bits may have garbage value.
+	  [ruby-dev:27513]
+
 Wed Oct 26 01:58:19 2005  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* configure.in (RUBY_EXTERN): macro to export symbols in shared
diff --git a/ruby.h b/ruby.h
index 1c8e07b60f..37e84b601a 100644
--- a/ruby.h
+++ b/ruby.h
@@ -170,10 +170,10 @@ VALUE rb_ull2inum _((unsigned LONG_LONG));
 #define SYM2ID(x) RSHIFT((long)x,8)
 
 /* special contants - i.e. non-zero and non-fixnum constants */
-#define Qfalse 0
-#define Qtrue  2
-#define Qnil   4
-#define Qundef 6		/* undefined value for placeholder */
+#define Qfalse ((VALUE)0)
+#define Qtrue  ((VALUE)2)
+#define Qnil   ((VALUE)4)
+#define Qundef ((VALUE)6)	/* undefined value for placeholder */
 
 #define RTEST(v) (((VALUE)(v) & ~Qnil) != 0)
 #define NIL_P(v) ((VALUE)(v) == Qnil)