diff --git a/docs/changelog.rst b/docs/changelog.rst
index d22fc600..476753da 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -4,6 +4,7 @@ Changelog
 
 Changes in 0.8.X
 ================
+- ImageFields now support inline replacements (#86)
 - Added SequenceField.set_next_value(value) helper (#159)
 - Updated .only() behaviour - now like exclude it is chainable (#202)
 - Added with_limit_and_skip support to count() (#235)
diff --git a/mongoengine/fields.py b/mongoengine/fields.py
index 4fc65c7e..45304291 100644
--- a/mongoengine/fields.py
+++ b/mongoengine/fields.py
@@ -1165,13 +1165,11 @@ class FileField(BaseField):
                     grid_file.delete()
                 except:
                     pass
-                # Create a new file with the new data
-                grid_file.put(value)
-            else:
-                # Create a new proxy object as we don't already have one
-                instance._data[key] = self.proxy_class(key=key, instance=instance,
-                                                       collection_name=self.collection_name)
-                instance._data[key].put(value)
+
+            # Create a new proxy object as we don't already have one
+            instance._data[key] = self.proxy_class(key=key, instance=instance,
+                                                   collection_name=self.collection_name)
+            instance._data[key].put(value)
         else:
             instance._data[key] = value
 
@@ -1208,6 +1206,8 @@ class ImageGridFsProxy(GridFSProxy):
         Insert a image in database
         applying field properties (size, thumbnail_size)
         """
+        if not self.instance:
+            import ipdb; ipdb.set_trace();
         field = self.instance._fields[self.key]
 
         try:
@@ -1235,10 +1235,7 @@ class ImageGridFsProxy(GridFSProxy):
             size = field.thumbnail_size
 
             if size['force']:
-                thumbnail = ImageOps.fit(img,
-                                   (size['width'],
-                                    size['height']),
-                                   Image.ANTIALIAS)
+                thumbnail = ImageOps.fit(img, (size['width'], size['height']), Image.ANTIALIAS)
             else:
                 thumbnail = img.copy()
                 thumbnail.thumbnail((size['width'],
@@ -1246,8 +1243,7 @@ class ImageGridFsProxy(GridFSProxy):
                                     Image.ANTIALIAS)
 
         if thumbnail:
-            thumb_id = self._put_thumbnail(thumbnail,
-                                          img_format)
+            thumb_id = self._put_thumbnail(thumbnail, img_format)
         else:
             thumb_id = None
 
@@ -1350,7 +1346,7 @@ class ImageField(FileField):
             if isinstance(att, (tuple, list)):
                 if PY3:
                     value = dict(itertools.zip_longest(params_size, att,
-                                                        fillvalue=None))
+                                                       fillvalue=None))
                 else:
                     value = dict(map(None, params_size, att))
 
diff --git a/tests/fields/file_tests.py b/tests/fields/file_tests.py
index 44d28626..c5842d81 100644
--- a/tests/fields/file_tests.py
+++ b/tests/fields/file_tests.py
@@ -16,6 +16,7 @@ from mongoengine.connection import get_db
 from mongoengine.python_support import PY3, b, StringIO
 
 TEST_IMAGE_PATH = os.path.join(os.path.dirname(__file__), 'mongoengine.png')
+TEST_IMAGE2_PATH = os.path.join(os.path.dirname(__file__), 'mongodb_leaf.png')
 
 
 class FileTest(unittest.TestCase):
@@ -217,6 +218,19 @@ class FileTest(unittest.TestCase):
         self.assertEqual(marmot.photo.content_type, 'image/jpeg')
         self.assertEqual(marmot.photo.foo, 'bar')
 
+    def test_file_reassigning(self):
+        class TestFile(Document):
+            the_file = FileField()
+        TestFile.drop_collection()
+
+        test_file = TestFile(the_file=open(TEST_IMAGE_PATH, 'rb')).save()
+        self.assertEqual(test_file.the_file.get().length, 8313)
+
+        test_file = TestFile.objects.first()
+        test_file.the_file = open(TEST_IMAGE2_PATH, 'rb')
+        test_file.save()
+        self.assertEqual(test_file.the_file.get().length, 4971)
+
     def test_file_boolean(self):
         """Ensure that a boolean test of a FileField indicates its presence
         """
@@ -264,6 +278,22 @@ class FileTest(unittest.TestCase):
 
         t.image.delete()
 
+    def test_image_field_reassigning(self):
+        if PY3:
+            raise SkipTest('PIL does not have Python 3 support')
+
+        class TestFile(Document):
+            the_file = ImageField()
+        TestFile.drop_collection()
+
+        test_file = TestFile(the_file=open(TEST_IMAGE_PATH, 'rb')).save()
+        self.assertEqual(test_file.the_file.size, (371, 76))
+
+        test_file = TestFile.objects.first()
+        test_file.the_file = open(TEST_IMAGE2_PATH, 'rb')
+        test_file.save()
+        self.assertEqual(test_file.the_file.size, (45, 101))
+
     def test_image_field_resize(self):
         if PY3:
             raise SkipTest('PIL does not have Python 3 support')
diff --git a/tests/fields/mongodb_leaf.png b/tests/fields/mongodb_leaf.png
new file mode 100644
index 00000000..36661cef
Binary files /dev/null and b/tests/fields/mongodb_leaf.png differ