diff --git a/Jamfile b/Jamfile
index 7e37136..98f02c2 100644
--- a/Jamfile
+++ b/Jamfile
@@ -3,6 +3,8 @@
 # Distributed under the Boost Software License, Version 1.0.
 # (See accompanying file LICENSE_1_0.txt or copy at http://boost.org/LICENSE_1_0.txt)
 
+require-b2 5.1 ;
+
 import option ;
 import path ;