diff --git a/test_transaction.py b/test_transaction.py
index fcd497f5..db34895e 100644
--- a/test_transaction.py
+++ b/test_transaction.py
@@ -1,16 +1,16 @@
 from pytest import raises
 
 
-def test_fulfillment_serialization(ffill_uri, user_vk):
+def test_fulfillment_serialization(ffill, user_vk):
     from bigchaindb.transaction import (
         Fulfillment,
     )
 
-    ffill = Fulfillment(ffill_uri, [user_vk])
+    ffill = Fulfillment(ffill, [user_vk])
     ffill_dict = ffill.to_dict()
     assert ffill_dict['owners_before'] == [user_vk]
     assert ffill_dict['input'] == None
-    assert ffill_dict['fulfillment'] == ffill_uri
+    assert ffill_dict['fulfillment'] == ffill.fulfillment.serialize_uri()
     assert ffill_dict['fid'] == 0
 
 
@@ -29,38 +29,36 @@ def test_fulfillment_deserialization(ffill_uri, user_vk):
     assert Fulfillment.from_dict(ffill_dict).to_dict() == ffill_dict
 
 
-def test_invalid_fulfillment_initialization(ffill_uri, user_vk):
+def test_invalid_fulfillment_initialization(ffill, user_vk):
     from bigchaindb.transaction import (
         Fulfillment,
     )
     with raises(TypeError):
-        Fulfillment(ffill_uri, user_vk)
+        Fulfillment(ffill, user_vk)
 
 
-def test_condition_serialization(cond_uri, user_vk):
+def test_condition_serialization(user_vk):
     from bigchaindb.transaction import (
         Condition,
     )
 
-    cond = Condition(cond_uri, [user_vk])
+    cond = Condition.gen_default(user_vk)
     cond_dict = cond.to_dict()
     assert cond_dict['owners_after'] == [user_vk]
-    assert cond_dict['condition']['uri'] == cond_uri
+    assert cond_dict['condition']['uri'] == cond.condition.condition_uri
     assert cond_dict['cid'] == 0
 
 
-def test_condition_deserialization(cond_uri, user_vk):
+def test_condition_deserialization(user_vk):
     from bigchaindb.transaction import (
         Condition,
     )
-    from cryptoconditions import (
-        Condition as CCCondition,
-    )
 
+    cond = Condition.gen_default(user_vk)
     cond_dict = {
         'condition': {
-            'uri': cond_uri,
-            'details': CCCondition.from_uri(cond_uri).to_dict()
+            'uri': cond.condition.condition_uri,
+            'details': cond.condition.to_dict()
         },
         'owners_after': [user_vk],
         'cid': 0,
@@ -69,12 +67,12 @@ def test_condition_deserialization(cond_uri, user_vk):
     assert Condition.from_dict(cond_dict).to_dict() == cond_dict
 
 
-def test_invalid_condition_initialization(cond_uri, user_vk):
+def test_invalid_condition_initialization(ffill, user_vk):
     from bigchaindb.transaction import (
         Condition,
     )
     with raises(TypeError):
-        Condition(cond_uri, user_vk)
+        Condition(ffill.condition, user_vk)
 
 
 def test_gen_default_condition(user_vk):
@@ -82,8 +80,39 @@ def test_gen_default_condition(user_vk):
         Condition,
     )
     from cryptoconditions import Ed25519Fulfillment
-    cond = Condition.gen_default_condition(user_vk)
+    cond = Condition.gen_default(user_vk)
     assert cond.owners_after == [user_vk]
     assert cond.cid == 0
     # TODO: Would be nice if Cryptoconditions would implement a `__eq__` method
-    assert cond.condition.to_dict() == Ed25519Fulfillment(public_key=user_vk).condition.to_dict()
+    # NOTE: This doesn't make sense yet...
+    assert cond.condition.to_dict() == Ed25519Fulfillment(public_key=user_vk).to_dict()
+
+
+def test_create_default_transaction(user_vk):
+    from bigchaindb.transaction import (
+        Condition,
+        Transaction,
+    )
+    cond = Condition.gen_default(user_vk)
+    tx = Transaction([cond])
+    assert tx.conditions == [cond]
+    assert tx.fulfillments == []
+    assert tx.inputs is None
+    assert tx.payload is None
+
+
+def test_sign_default_transaction(user_vk, user_sk):
+    from bigchaindb.transaction import (
+        Fulfillment,
+        Transaction,
+    )
+
+    ffill = Fulfillment.gen_default(user_vk)
+    ffill.to_dict()
+    cond = ffill.gen_condition()
+    tx = Transaction(Transaction.CREATE, [ffill], [cond])
+    tx.sign([user_sk])
+    tx_dict = tx.to_dict()
+    # TODO: We need to make sure to serialize the transaction correctly!!!
+    assert len(tx.fulfillments) > 0
+    assert tx_dict['transaction']['conditions'][0] == cond.to_dict()