diff --git a/tests/document/instance.py b/tests/document/instance.py
index 978488f1..ba01db4c 100644
--- a/tests/document/instance.py
+++ b/tests/document/instance.py
@@ -13,7 +13,7 @@ from datetime import datetime
 from bson import DBRef, ObjectId
 from tests import fixtures
 from tests.fixtures import (PickleEmbedded, PickleTest, PickleSignalsTest,
-                            PickleDyanmicEmbedded, PickleDynamicTest)
+                            PickleDynamicEmbedded, PickleDynamicTest)
 
 from mongoengine import *
 from mongoengine.errors import (NotRegistered, InvalidDocumentError,
@@ -2317,7 +2317,7 @@ class InstanceTest(unittest.TestCase):
 
         pickle_doc = PickleDynamicTest(
             name="test", number=1, string="One", lists=['1', '2'])
-        pickle_doc.embedded = PickleDyanmicEmbedded(foo="Bar")
+        pickle_doc.embedded = PickleDynamicEmbedded(foo="Bar")
         pickled_doc = pickle.dumps(pickle_doc)  # make sure pickling works even before the doc is saved
 
         pickle_doc.save()
diff --git a/tests/fixtures.py b/tests/fixtures.py
index b3bf73e8..d8eb8487 100644
--- a/tests/fixtures.py
+++ b/tests/fixtures.py
@@ -26,7 +26,7 @@ class NewDocumentPickleTest(Document):
     new_field = StringField()
 
 
-class PickleDyanmicEmbedded(DynamicEmbeddedDocument):
+class PickleDynamicEmbedded(DynamicEmbeddedDocument):
     date = DateTimeField(default=datetime.now)
 
 
diff --git a/tests/migration/__init__.py b/tests/migration/__init__.py
index 6fc83e02..ef62d876 100644
--- a/tests/migration/__init__.py
+++ b/tests/migration/__init__.py
@@ -1,8 +1,11 @@
+import unittest
+
 from convert_to_new_inheritance_model import *
 from decimalfield_as_float import *
-from refrencefield_dbref_to_object_id import *
+from referencefield_dbref_to_object_id import *
 from turn_off_inheritance import *
 from uuidfield_to_binary import *
 
+
 if __name__ == '__main__':
     unittest.main()
diff --git a/tests/migration/refrencefield_dbref_to_object_id.py b/tests/migration/referencefield_dbref_to_object_id.py
similarity index 100%
rename from tests/migration/refrencefield_dbref_to_object_id.py
rename to tests/migration/referencefield_dbref_to_object_id.py
diff --git a/tests/test_dereference.py b/tests/test_dereference.py
index e1ae3740..11bdd612 100644
--- a/tests/test_dereference.py
+++ b/tests/test_dereference.py
@@ -12,9 +12,13 @@ from mongoengine.context_managers import query_counter
 
 class FieldTest(unittest.TestCase):
 
-    def setUp(self):
-        connect(db='mongoenginetest')
-        self.db = get_db()
+    @classmethod
+    def setUpClass(cls):
+        cls.db = connect(db='mongoenginetest')
+
+    @classmethod
+    def tearDownClass(cls):
+        cls.db.drop_database('mongoenginetest')
 
     def test_list_item_dereference(self):
         """Ensure that DBRef items in ListFields are dereferenced.
@@ -304,6 +308,7 @@ class FieldTest(unittest.TestCase):
 
         User.drop_collection()
         Post.drop_collection()
+        SimpleList.drop_collection()
 
         u1 = User.objects.create(name='u1')
         u2 = User.objects.create(name='u2')