diff --git a/spanner/google/cloud/spanner/streamed.py b/spanner/google/cloud/spanner/streamed.py
index c7d950d766d7..e4323ef2376e 100644
--- a/spanner/google/cloud/spanner/streamed.py
+++ b/spanner/google/cloud/spanner/streamed.py
@@ -305,6 +305,8 @@ def _merge_struct(lhs, rhs, type_):
     type_pb2.ARRAY: _merge_array,
     type_pb2.STRUCT: _merge_struct,
     type_pb2.BYTES: _merge_string,
+    type_pb2.DATE: _merge_string,
+    type_pb2.TIMESTAMP: _merge_string,
 }