diff --git a/ChangeLog b/ChangeLog
index 9683193882..c1b937f81b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Oct  7 23:44:33 2006  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* bignum.c (rb_big_rshift): a bug in right shift of negative
+	  bignums.  [ruby-core:09020]
+
 Sat Oct  7 23:33:02 2006  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* eval.c (formal_assign): packed post splat arguments may conflict
diff --git a/bignum.c b/bignum.c
index ecf2872f08..17424b5148 100644
--- a/bignum.c
+++ b/bignum.c
@@ -1811,6 +1811,10 @@ rb_big_rshift(VALUE x, VALUE y)
     }
     xds = BDIGITS(x);
     i = RBIGNUM(x)->len; j = i - s1;
+    if (j == 0) {
+	if (RBIGNUM(x)->sign) return INT2FIX(0);
+	else return INT2FIX(-1);
+    }
     z = bignew(j, RBIGNUM(x)->sign);
     if (!RBIGNUM(x)->sign) {
 	num = ((BDIGIT_DBL)~0) << BITSPERDIG;