diff --git a/jira/client.py b/jira/client.py
index 8ecb3851f..7d62e9596 100644
--- a/jira/client.py
+++ b/jira/client.py
@@ -1207,11 +1207,14 @@ def group_members(self, group):
 
         result = {}
         for user in r["users"]["items"]:
-            result[user["key"]] = {
-                "name": user["name"],
-                "fullname": user["displayName"],
-                "email": user.get("emailAddress", "hidden"),
-                "active": user["active"],
+            result[user['id']] = {
+                'name': user.get('name'),
+                'id': user.get('id'),
+                'accountId': user.get('accountId'),
+                'fullname': user.get('displayName'),
+                'email': user.get('emailAddress', 'hidden'),
+                'active': user.get('active'),
+                'timezone': user.get('timezone')
             }
         return OrderedDict(sorted(result.items(), key=lambda t: t[0]))