diff --git a/ChangeLog b/ChangeLog
index 112c5d1c43..ba82ec467f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Tue May 11 14:10:36 2010  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* time.c (rb_big_abs_find_minbit): get rid of a warning of VC.
+
 Tue May 11 14:09:21 2010  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* win32/win32.c, include/ruby/win32.h (rb_w32_has_cancel_io): new
diff --git a/time.c b/time.c
index 62e4235603..7bd5c28cb3 100644
--- a/time.c
+++ b/time.c
@@ -345,7 +345,7 @@ rb_big_abs_find_minbit(VALUE big)
         return Qnil;
     res = mul(LONG2NUM(i), INT2FIX(SIZEOF_BDIGITS * CHAR_BIT));
     d = ds[i];
-    res = add(res, LONG2FIX(bdigit_find_maxbit(d & -d)));
+    res = add(res, LONG2FIX(bdigit_find_maxbit(d & (~d-1))));
     return res;
 }