diff --git a/setup.py b/setup.py
index 1422d43..394ca8f 100644
--- a/setup.py
+++ b/setup.py
@@ -13,10 +13,7 @@
     url='http://github.com/svetlyak40wt/django-fields/',
     install_requires=[
         'django',
-        'pycrypto',
-        'nose',
-        'django-nose==1.4.4',
-        'tox',
+        'pycryptodome',
     ],
     classifiers=[
         'Development Status :: 2 - Pre-Alpha',
diff --git a/src/django_fields/fields.py b/src/django_fields/fields.py
index 3611510..4b3b17f 100644
--- a/src/django_fields/fields.py
+++ b/src/django_fields/fields.py
@@ -66,7 +66,7 @@ def __init__(self, *args, **kwargs):
                 getattr(self.cipher_object, self.block_type),
                 self.iv)
         else:
-            self.cipher = self.cipher_object.new(self.secret_key)
+            self.cipher = self.cipher_object.new(self.secret_key, self.cipher_object.MODE_ECB)
             self.prefix = '$%s$' % self.cipher_type
 
         self.original_max_length = max_length = kwargs.get('max_length', 40)