diff --git a/mozilla/xpcom/reflect/xptcall/src/md/unix/Makefile.in b/mozilla/xpcom/reflect/xptcall/src/md/unix/Makefile.in
index d150df3af35..463afa7e058 100644
--- a/mozilla/xpcom/reflect/xptcall/src/md/unix/Makefile.in
+++ b/mozilla/xpcom/reflect/xptcall/src/md/unix/Makefile.in
@@ -376,7 +376,7 @@ FORCE_STATIC_LIB = 1
 
 include $(topsrcdir)/config/rules.mk
 
-DEFINES		+= -DEXPORT_XPTC_API
+DEFINES		+= -DEXPORT_XPTC_API -D_IMPL_NS_COM
 
 INCLUDES	+= -I$(srcdir)/../..