Index: tools/build/v2/build/feature.jam
===================================================================
--- tools/build/v2/build/feature.jam	(revision 48679)
+++ tools/build/v2/build/feature.jam	(working copy)
@@ -454,7 +454,9 @@
 
         if $($(feature).subfeatures)
         {
-            values = [ regex.split $(value-string) - ] ;
+            if ! ( $(value-string) in $($(feature).subfeatures) ) {
+                values = [ regex.split $(value-string) - ] ;
+            }
         }
 
         if ! ( $(values[1]) in $($(feature).values) ) &&