diff --git a/mozilla/xpcom/build/makefile.win b/mozilla/xpcom/build/makefile.win
index 575b5718da8..2ab1853e246 100644
--- a/mozilla/xpcom/build/makefile.win
+++ b/mozilla/xpcom/build/makefile.win
@@ -20,6 +20,8 @@ IGNORE_MANIFEST=1
 DEPTH=..\..
 MODULE = xpcom 
 
+include <$(DEPTH)\config\config.mak>
+
 LIBNAME = .\$(OBJDIR)\xpcom
 DLL = $(LIBNAME).dll