--- a/mod_http_admin_api/mod_http_admin_api.lua	Thu Jan 21 14:42:11 2021 +0000
+++ b/mod_http_admin_api/mod_http_admin_api.lua	Thu Jan 21 15:51:07 2021 +0100
@@ -336,8 +336,10 @@
 	end
 
 	if property == "groups" then
+		event.response.headers["Content-Type"] = json_content_type;
 		return json.encode(get_user_groups(username));
 	elseif property == "debug" then
+		event.response.headers["Content-Type"] = json_content_type;
 		return json.encode(get_user_debug_info(username));
 	end