diff --git a/ChangeLog b/ChangeLog
index 68e8b13f3e..dc8f5da8de 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Jan 22 00:30:08 2008  Yusuke Endoh  <mame@tsg.ne.jp>
+
+	* bignum.c (big_shift): fix a bug that caused infinite loop when
+	  left shifting.
+
 Mon Jan 21 20:09:38 2008  Tadayoshi Funaba  <tadf@dotrb.org>
 
 	* lib/date.rb (marshal_load): initialize the cache.
diff --git a/bignum.c b/bignum.c
index 8b694d91ae..5ed026acdf 100644
--- a/bignum.c
+++ b/bignum.c
@@ -1851,7 +1851,7 @@ static VALUE big_rshift(VALUE, unsigned long);
 static VALUE big_shift(VALUE x, int n)
 {
     if (n < 0)
-	return big_lshift(x, (unsigned int)n);
+	return big_lshift(x, (unsigned int)-n);
     else if (n > 0)
 	return big_rshift(x, (unsigned int)n);
     return x;