diff --git a/extras_mongoengine/django_fields.py b/extras_mongoengine/django_fields.py
index ee0f2a8..1f4b08e 100755
--- a/extras_mongoengine/django_fields.py
+++ b/extras_mongoengine/django_fields.py
@@ -70,7 +70,7 @@ def generate_filename(self, instance, filename):
         return os.path.join(
                 self.get_directory_name(), self.get_filename(filename))
 
-    def to_mongo(self, value):
+    def to_mongo(self, value, **kwargs):
         if isinstance(value, self.proxy_class):
             return value.name
         return value
diff --git a/extras_mongoengine/fields.py b/extras_mongoengine/fields.py
index 5871ddf..d1840b5 100644
--- a/extras_mongoengine/fields.py
+++ b/extras_mongoengine/fields.py
@@ -14,7 +14,7 @@ def validate(self, value):
         if not isinstance(value, (timedelta, int, float)):
             self.error(u'cannot parse timedelta "%r"' % value)
 
-    def to_mongo(self, value):
+    def to_mongo(self, value, **kwargs):
         return self.prepare_query_value(None, value)
 
     def to_python(self, value):
@@ -84,7 +84,7 @@ def __get_value(self, enum):
     def to_python(self, value):
         return self.enum(super(EnumField, self).to_python(value))
 
-    def to_mongo(self, value):
+    def to_mongo(self, value, **kwargs):
         return self.__get_value(value)
 
     def prepare_query_value(self, op, value):