--- src/tools/port/jam/Jamdefs	2008-10-30 10:11:39.000000000 +0100
+++ src/tools/port/jam/Jamdefs	2008-10-30 10:12:03.000000000 +0100
@@ -2053,7 +2053,7 @@
     }
     else
     {
-	XERCESCLIB = libxerces-c.$(SLSFX).$(XERCVERS).0 ;
+	XERCESCLIB ?= libxerces-c.$(SLSFX).$(XERCVERS).0 ;
     }
 }
 else