diff --git a/src/calibre/gui2/dialogs/metadata_single.py b/src/calibre/gui2/dialogs/metadata_single.py
index 63195f025a..20a3d2a480 100644
--- a/src/calibre/gui2/dialogs/metadata_single.py
+++ b/src/calibre/gui2/dialogs/metadata_single.py
@@ -552,6 +552,8 @@ class MetadataSingleDialog(ResizableDialog, Ui_MetadataSingleDialog):
                                 warning_dialog(self, _('There were errors'),
                                        _('There were errors downloading social metadata'),
                                        det_msg=det, show=True)
+                        else:
+                            book.tags = []
                         self.title.setText(book.title)
                         self.authors.setText(authors_to_string(book.authors))
                         if book.author_sort: self.author_sort.setText(book.author_sort)
diff --git a/src/calibre/gui2/metadata.py b/src/calibre/gui2/metadata.py
index d6c11c3bb6..0502401943 100644
--- a/src/calibre/gui2/metadata.py
+++ b/src/calibre/gui2/metadata.py
@@ -100,6 +100,8 @@ class DownloadMetadata(Thread):
                     mi.smart_update(fmi)
                     if mi.isbn and self.get_social_metadata:
                         self.social_metadata_exceptions = get_social_metadata(mi)
+                    if not self.get_social_metadata:
+                        mi.tags = []
                 else:
                     self.failures[id] = (mi.title,
                         _('No matches found for this book'))