Index: boost-build.jam
===================================================================
--- boost-build.jam	(revision 49596)
+++ boost-build.jam	(working copy)
@@ -21,6 +21,7 @@
 local boost-src = [ if-has-file configure :
     [ MATCH --boost=(.*) : $(ARGV) ]
     $(BOOST)
+    $(BOOST_ROOT)
     $(.boost-build-file:D)/../boost
     ] ;