diff --git a/beets/library.py b/beets/library.py
index 7c1bd5075..44ca3540d 100644
--- a/beets/library.py
+++ b/beets/library.py
@@ -590,13 +590,16 @@ class FormattedItemMapping(dbcore.db.FormattedMapping):
                 if key in Album.item_keys or key not in item._fields.keys():
                     self.album_keys.append(key)
 
-    def get(self, key):
+    def get(self, key, default=None):
         if key in self.album_keys:
             return self.album._get_formatted(key, self.for_path)
         elif key in self.model_keys:
             return self.model._get_formatted(key, self.for_path)
         else:
-            raise KeyError(key)
+            if default is None:
+                raise KeyError(key)
+            else:
+                return default
 
     def __getitem__(self, key):
         value = self.get(key)
diff --git a/beets/ui/__init__.py b/beets/ui/__init__.py
index e798fed2d..00b217850 100644
--- a/beets/ui/__init__.py
+++ b/beets/ui/__init__.py
@@ -576,8 +576,8 @@ def _field_diff(field, old, new):
         return None
 
     # Get formatted values for output.
-    oldstr = old.formatted.get(field) or u''
-    newstr = new.formatted.get(field) or u''
+    oldstr = old.formatted.get(field, u'')
+    newstr = new.formatted.get(field, u'')
 
     # For strings, highlight changes. For others, colorize the whole
     # thing.
diff --git a/test/test_ui.py b/test/test_ui.py
index d28587c0a..e1190b621 100644
--- a/test/test_ui.py
+++ b/test/test_ui.py
@@ -225,6 +225,14 @@ class ModifyTest(_common.TestCase):
         mediafile = MediaFile(item.path)
         self.assertEqual(mediafile.initial_key, 'C#m')
 
+    def test_remove_flexattr(self):
+        self._modify(["flexattr=testAttr"], write=True)
+        item = self.lib.items().get()
+        self.assertEqual(item.flexattr, 'testAttr')
+        self._modify(dels=["flexattr"], write=True)
+        item = self.lib.items().get()
+        self.assertTrue("flexattr" not in item)
+
     @unittest.skip('not yet implemented')
     def test_delete_initial_key_tag(self):
         item = self.i