--- src/tools/port/jam/Jamdefs	2008-10-28 14:07:42.000000000 +0100
+++ src/tools/port/jam/Jamdefs	2008-10-30 11:23:47.000000000 +0100
@@ -2069,7 +2069,7 @@
     }
     else
     {
-	XERCESCLIB = libxerces-c.$(SLSFX).$(XERCVERS).0 ;
+	XERCESCLIB ?= libxerces-c.$(SLSFX).$(XERCVERS).0 ;
     }
 }
 else