diff --git a/manifest.json b/manifest.json
index 891a4edf..28c8dc9b 100644
--- a/manifest.json
+++ b/manifest.json
@@ -327,6 +327,7 @@
 		"20-10",
 		"20-11",
 		"20-12",
+		"20-13",
 		"21-title",
 		"22-title",
 		"31-reference"