diff --git a/tensorflow/python/client/session.py b/tensorflow/python/client/session.py
index 8d1be4b26ed..52c57a3a1ab 100644
--- a/tensorflow/python/client/session.py
+++ b/tensorflow/python/client/session.py
@@ -413,10 +413,9 @@ class _DictFetchMapper(_FetchMapper):
     return self._unique_fetches
 
   def build_results(self, values):
-    results = self._fetch_type()
-    for k, m, vi in zip(self._keys, self._mappers, self._value_indices):
-      results[k] = m.build_results([values[j] for j in vi])
-    return results
+    return self._fetch_type(
+        (k, m.build_results([values[j] for j in vi]))
+        for k, m, vi in zip(self._keys, self._mappers, self._value_indices))
 
 
 class _AttrsFetchMapper(_FetchMapper):