diff --git a/archivebox/core/admin.py b/archivebox/core/admin.py
index 4dbc2ff7..d539d3f1 100644
--- a/archivebox/core/admin.py
+++ b/archivebox/core/admin.py
@@ -49,7 +49,6 @@ from django.contrib.admin.helpers import ActionForm
 
 class SnapshotActionForm(ActionForm):
     tag = forms.ModelChoiceField(queryset=Tag.objects.all(), required=False)
-    # pass
 
 
 class SnapshotAdmin(SearchResultsAdminMixin, admin.ModelAdmin):
@@ -214,9 +213,10 @@ class SnapshotAdmin(SearchResultsAdminMixin, admin.ModelAdmin):
     delete_snapshots.short_description = "Delete"
 
     def add_tag(self, request, queryset):
-        tag = request.POST['tag']
-        for obj in queryset:
-            obj.tags.add(tag)
+        if tag and tag.id:
+            tag = request.POST['tag']
+            for obj in queryset:
+                obj.tags.add(tag)
 
     add_tag.short_description = "Add tag"
 
diff --git a/archivebox/core/models.py b/archivebox/core/models.py
index 72eed2c3..8cd2b1a9 100644
--- a/archivebox/core/models.py
+++ b/archivebox/core/models.py
@@ -32,8 +32,8 @@ class Tag(models.Model):
     """
     Based on django-taggit model
     """
-    name = models.CharField(verbose_name="name", unique=True, blank=False, max_length=100)
-    slug = models.SlugField(verbose_name="slug", unique=True, blank=True, max_length=100)
+    name = models.CharField(unique=True, blank=False, max_length=100)
+    slug = models.SlugField(unique=True, blank=True, max_length=100)
 
     class Meta:
         verbose_name = "Tag"