diff --git a/src/calibre/gui2/tag_view.py b/src/calibre/gui2/tag_view.py
index 235251f8ea..39135fec27 100644
--- a/src/calibre/gui2/tag_view.py
+++ b/src/calibre/gui2/tag_view.py
@@ -1092,6 +1092,7 @@ class TagsModel(QAbstractItemModel): # {{{
                         if comp in child_map:
                             node_parent = child_map[comp]
                             node_parent.tag.count += tag.count
+                            node_parent.tag.use_prefix = True
                         else:
                             if i < len(components)-1:
                                 t = copy.copy(tag)