diff --git a/mozilla/layout/mathml/content/src/Makefile.in b/mozilla/layout/mathml/content/src/Makefile.in
index d874cddf2a3..1ae44b60a60 100644
--- a/mozilla/layout/mathml/content/src/Makefile.in
+++ b/mozilla/layout/mathml/content/src/Makefile.in
@@ -68,5 +68,5 @@ EXPORT_RESOURCE_CONTENT = \
 		$(NULL)
 install::
 	$(INSTALL) $(EXPORT_RESOURCE_CONTENT) $(DIST)/bin/dtd
-	$(INSTALL) mathml.css $(DIST)/bin/res
-	$(PERL) mathml-css.pl $(DIST)/bin/res/ua.css
+	$(INSTALL) $(srcdir)/mathml.css $(DIST)/bin/res
+	$(PERL) $(srcdir)/mathml-css.pl $(DIST)/bin/res/ua.css