diff --git a/manifest.json b/manifest.json
index 6ce91584..9e3c4d74 100644
--- a/manifest.json
+++ b/manifest.json
@@ -335,6 +335,7 @@
 		"21-03",
 		"21-04",
 		"21-05",
+		"21-06",
 		"22-title",
 		"31-reference"
 	]