diff --git a/scripts/Makefile.frag b/scripts/Makefile.frag
index 6e0a26c38ae..7c40b41b5ca 100644
--- a/scripts/Makefile.frag
+++ b/scripts/Makefile.frag
@@ -29,6 +29,7 @@ HEADER_DIRS = \
 	main/ \
 	main/streams/ \
 	regex/ \
+	ext/libxml/ \
 	ext/standard/ \
 	ext/session/ \
 	ext/xml/ \