diff --git a/python/smqtk/algorithms/nn_index/hash_index/linear.py b/python/smqtk/algorithms/nn_index/hash_index/linear.py
index 8a84d726c..e8924402f 100644
--- a/python/smqtk/algorithms/nn_index/hash_index/linear.py
+++ b/python/smqtk/algorithms/nn_index/hash_index/linear.py
@@ -119,7 +119,7 @@ def load_cache(self):
         with self._model_lock:
             if self.cache_element and not self.cache_element.is_empty():
                 buff = BytesIO(self.cache_element.get_bytes())
-                self.index = set(numpy.load(buff))
+                self.index = set(numpy.load(buff, allow_pickle=True))
 
     def save_cache(self):
         """