diff --git a/bigchaindb/common/transaction.py b/bigchaindb/common/transaction.py
index b1c8fe44..f5e8239e 100644
--- a/bigchaindb/common/transaction.py
+++ b/bigchaindb/common/transaction.py
@@ -28,7 +28,7 @@ from bigchaindb.common.exceptions import (KeypairMismatchException,
                                           AmountError, AssetIdMismatch,
                                           ThresholdTooDeep)
 from bigchaindb.common.utils import serialize
-from .memoize import memoize_from_dict  # , memoize_to_dict
+from .memoize import memoize_from_dict, memoize_to_dict
 
 
 UnspentOutput = namedtuple(
@@ -1061,7 +1061,7 @@ class Transaction(object):
     def __hash__(self):
         return hash(self.id)
 
-    # @memoize_to_dict
+    @memoize_to_dict
     def to_dict(self):
         """Transforms the object to a Python dictionary.
 
diff --git a/tests/backend/localmongodb/test_queries.py b/tests/backend/localmongodb/test_queries.py
index 51e20265..e20214a0 100644
--- a/tests/backend/localmongodb/test_queries.py
+++ b/tests/backend/localmongodb/test_queries.py
@@ -202,7 +202,7 @@ def test_get_owned_ids(signed_create_tx, user_pk):
     conn = connect()
 
     # insert a transaction
-    conn.db.transactions.insert_one(signed_create_tx.to_dict())
+    conn.db.transactions.insert_one(deepcopy(signed_create_tx.to_dict()))
 
     txns = list(query.get_owned_ids(conn, user_pk))
 
@@ -221,7 +221,7 @@ def test_get_spending_transactions(user_pk, user_sk):
     tx2 = Transaction.transfer([inputs[0]], out, tx1.id).sign([user_sk])
     tx3 = Transaction.transfer([inputs[1]], out, tx1.id).sign([user_sk])
     tx4 = Transaction.transfer([inputs[2]], out, tx1.id).sign([user_sk])
-    txns = [tx.to_dict() for tx in [tx1, tx2, tx3, tx4]]
+    txns = [deepcopy(tx.to_dict()) for tx in [tx1, tx2, tx3, tx4]]
     conn.db.transactions.insert_many(txns)
 
     links = [inputs[0].fulfills.to_dict(), inputs[2].fulfills.to_dict()]