diff --git a/sloth/annotations/model.py b/sloth/annotations/model.py
index bb1f016..40acb9d 100644
--- a/sloth/annotations/model.py
+++ b/sloth/annotations/model.py
@@ -255,6 +255,7 @@ class RootModelItem(ModelItem):
     def appendFileItem(self, fileinfo):
         item = FileModelItem.create(fileinfo)
         self.appendChild(item)
+        return item
 
     def appendFileItems(self, fileinfos):
         start1 = time.time()
diff --git a/sloth/core/commands.py b/sloth/core/commands.py
index 9566a8f..284ae64 100644
--- a/sloth/core/commands.py
+++ b/sloth/core/commands.py
@@ -76,6 +76,10 @@ class AppendFilesCommand(BaseCommand):
     """
     args = '<labelfile> <file1> [<file2> ...]'
     help = __doc__.strip()
+    option_list = BaseCommand.option_list + (
+        make_option('-u', '--unlabeled', action='store_true', default=False,
+            help='Mark appended files as unlabeled.'),
+    )
 
     def handle(self, *args, **options):
         if len(args) < 2:
@@ -88,7 +92,9 @@ class AppendFilesCommand(BaseCommand):
                 rel_filename = os.path.relpath(filename, os.path.dirname(args[0]))
             except:
                 pass
-            self.labeltool.addImageFile(rel_filename)
+            item = self.labeltool.addImageFile(rel_filename)
+            if options['unlabeled']:
+                item.setUnlabeled(True)
         self.labeltool.saveAnnotations(args[0])
 
 
diff --git a/sloth/core/labeltool.py b/sloth/core/labeltool.py
index 8fcb19b..5b47d65 100755
--- a/sloth/core/labeltool.py
+++ b/sloth/core/labeltool.py
@@ -329,7 +329,7 @@ class LabelTool(QObject):
                 'class': 'image',
                 'annotations': [ ],
             }
-        self._model._root.appendFileItem(fileitem)
+        return self._model._root.appendFileItem(fileitem)
 
     def addVideoFile(self, fname):
         fileitem = {