diff --git a/dictionaries/attributes.definition.json b/dictionaries/attributes.definition.json
index 7728eaf8..27d79a20 100644
--- a/dictionaries/attributes.definition.json
+++ b/dictionaries/attributes.definition.json
@@ -20,6 +20,9 @@
 	"attribute_mail": {
 		"en": "Mail"
 	},
+	"attribute_ismemberof": {
+		"en": "Group membership"
+	},
 	"attribute_mobile": {
 		"en": "Mobile"
 	},