diff --git a/ndsl/halo/data_transformer.py b/ndsl/halo/data_transformer.py
index 9f9ab2f6..f3133974 100644
--- a/ndsl/halo/data_transformer.py
+++ b/ndsl/halo/data_transformer.py
@@ -225,9 +225,12 @@ def finalize(self):
         self.synchronize()
 
         # Push the buffers back in the cache
-        Buffer.push_to_cache(self._pack_buffer)
+        if self._pack_buffer is not None:
+            Buffer.push_to_cache(self._pack_buffer)
         self._pack_buffer = None
-        Buffer.push_to_cache(self._unpack_buffer)
+
+        if self._unpack_buffer is not None:
+            Buffer.push_to_cache(self._unpack_buffer)
         self._unpack_buffer = None
 
     @staticmethod