diff --git a/es_search.py b/es_search.py
index 8a6b4ac..74a3347 100644
--- a/es_search.py
+++ b/es_search.py
@@ -34,6 +34,8 @@ class ESSearch(PyOperator):
             raise e
 
     def __call__(self, index_name: str, query: dict = {'match_all': {}}):
+        if not query:
+            return ''
         resp = self.client.search(index=index_name, query=query)
         return resp