diff --git a/mozilla/xpcom/tests/Makefile.in b/mozilla/xpcom/tests/Makefile.in
index 6392c14e042..9f398d6197b 100644
--- a/mozilla/xpcom/tests/Makefile.in
+++ b/mozilla/xpcom/tests/Makefile.in
@@ -80,7 +80,7 @@ endif
 include $(topsrcdir)/config/rules.mk
 
 DEFINES		+= -DUSE_NSREG
-INCLUDES	+= -I$(srcdir)/../public
+INCLUDES	+= -I$(srcdir)/../public -I$(srcdir)/services
 
 install::
 	$(INSTALL) $(srcdir)/test.properties $(DIST)/bin/res