diff --git a/nomad/app/api/encyclopedia.py b/nomad/app/api/encyclopedia.py
index 8b4e29322c5e9836dc1055fba60785ce861e56d4..1b62c71cdb8f9f99b46f98a15d5466fffaef6ff6 100644
--- a/nomad/app/api/encyclopedia.py
+++ b/nomad/app/api/encyclopedia.py
@@ -17,7 +17,6 @@ The encyclopedia API of the nomad@FAIRDI APIs.
 """
 import re
 import math
-import json
 from typing import List, Dict, Union, Sequence
 
 from flask_restplus import Resource, abort, fields, marshal