diff --git a/docs/changelog.rst b/docs/changelog.rst
index 006dfc74..bc6f2832 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -5,6 +5,7 @@ Changelog
 
 Changes in 0.8.2
 ================
+- Removed unused var in _get_changed_fields (#347)
 - Added pre_save_post_validation signal (#345)
 - DateTimeField now auto converts valid datetime isostrings into dates (#343)
 - DateTimeField now uses dateutil for parsing if available (#343)
diff --git a/mongoengine/base/document.py b/mongoengine/base/document.py
index 2ffcbc57..e2944fb0 100644
--- a/mongoengine/base/document.py
+++ b/mongoengine/base/document.py
@@ -392,7 +392,7 @@ class BaseDocument(object):
                 if field_value:
                     field_value._clear_changed_fields()
 
-    def _get_changed_fields(self, key='', inspected=None):
+    def _get_changed_fields(self, inspected=None):
         """Returns a list of all fields that have explicitly been changed.
         """
         EmbeddedDocument = _import_class("EmbeddedDocument")
@@ -423,7 +423,7 @@ class BaseDocument(object):
             if (isinstance(field, (EmbeddedDocument, DynamicEmbeddedDocument))
                and db_field_name not in _changed_fields):
                  # Find all embedded fields that have been changed
-                changed = field._get_changed_fields(key, inspected)
+                changed = field._get_changed_fields(inspected)
                 _changed_fields += ["%s%s" % (key, k) for k in changed if k]
             elif (isinstance(field, (list, tuple, dict)) and
                     db_field_name not in _changed_fields):
@@ -437,7 +437,7 @@ class BaseDocument(object):
                     if not hasattr(value, '_get_changed_fields'):
                         continue
                     list_key = "%s%s." % (key, index)
-                    changed = value._get_changed_fields(list_key, inspected)
+                    changed = value._get_changed_fields(inspected)
                     _changed_fields += ["%s%s" % (list_key, k)
                                         for k in changed if k]
         return _changed_fields