diff --git a/boards/admin.py b/boards/admin.py
--- a/boards/admin.py
+++ b/boards/admin.py
@@ -56,6 +56,15 @@ class ThreadAdmin(admin.ModelAdmin):
     def op(self, obj: Thread):
         return obj.get_opening_post_id()
 
+    # Save parent tags when editing tags
+    def save_related(self, request, form, formsets, change):
+        super().save_related(request, form, formsets, change)
+        obj = form.instance
+        for tag in obj.get_tags().all():
+            parents = tag.get_all_parents()
+            if len(parents) > 0:
+                obj.tags.add(*parents)
+
     list_display = ('id', 'op', 'title', 'reply_count', 'status', 'ip',
             'display_tags')
     list_filter = ('bump_time', 'status')