diff --git a/gramps/plugins/database/dictionarydb.py b/gramps/plugins/database/dictionarydb.py
index 3641b77a5..a1c0afdb8 100644
--- a/gramps/plugins/database/dictionarydb.py
+++ b/gramps/plugins/database/dictionarydb.py
@@ -520,6 +520,11 @@ class DictionaryDb(DbGeneric):
         emit = None
         if tag.handle in self.tag_map:
             emit = "tag-update"
+            existing_names = [existing_name for existing_name, existing_tag in
+                    self._tag_name_dict.items()
+                    if existing_tag.handle == tag.handle]
+            for existing_name in existing_names:
+                del self._tag_name_dict[existing_name]
             self._tag_dict[tag.handle] = tag
             self._tag_name_dict[tag.name] = tag
         else: