Index: boostcpp.jam
--- boostcpp.jam.orig
+++ boostcpp.jam
@@ -35,6 +35,7 @@ import version : version-less ;
 
 BOOST_ROOT = [ modules.binding $(__name__) ] ;
 BOOST_ROOT = $(BOOST_ROOT:D) ;
+SO_VERSION = ${SO_VERSION} ;
 
 rule set-version ( version )
 {
@@ -212,7 +213,7 @@ rule tag ( name : type ? : property-set )
           ! [ $(property-set).get <target-os> ] in windows cygwin darwin aix android &&
           ! [ $(property-set).get <toolset> ] in pgi
         {
-            result = $(result).$(BOOST_VERSION)  ;
+            result = $(result).$(SO_VERSION)  ;
         }
 
         return $(result) ;
