diff --git a/src/calibre/db/lazy.py b/src/calibre/db/lazy.py
index 2899f85b27..2d0d7de036 100644
--- a/src/calibre/db/lazy.py
+++ b/src/calibre/db/lazy.py
@@ -10,6 +10,7 @@ from collections.abc import MutableMapping, MutableSequence
 from copy import deepcopy
 from functools import wraps
 
+from calibre.ebooks.metadata.book import STANDARD_METADATA_FIELDS
 from calibre.ebooks.metadata.book.base import ALL_METADATA_FIELDS, NULL_VALUES, SIMPLE_GET, TOP_LEVEL_IDENTIFIERS, Metadata
 from calibre.ebooks.metadata.book.formatter import SafeFormat
 from calibre.utils.date import utcnow
@@ -387,7 +388,6 @@ class ProxyMetadata(Metadata):
                                    "Use the explicit methods such as all_field_keys()")
 
     def has_key(self, key):
-        from calibre.ebooks.metadata.book import STANDARD_METADATA_FIELDS
         return key in STANDARD_METADATA_FIELDS or key in ga(self, '_user_metadata')
 
     def deepcopy(self, **kwargs):