diff --git a/tests/load_es_data.py b/tests/load_es_data.py
index 073f8d4..0d12cd1 100644
--- a/tests/load_es_data.py
+++ b/tests/load_es_data.py
@@ -92,7 +92,7 @@ def gendata(data):
 # create index
 es.indices.create(index=index_name, body=settings, request_timeout=90)
 
-with open(sys.argv[1]) as fh:
+with open(sys.argv[1], encoding='utf-8') as fh:
     d = json.load(fh)
 
     # call generator function to yield features into ES build API