diff --git a/src/calibre/gui2/metadata/basic_widgets.py b/src/calibre/gui2/metadata/basic_widgets.py
index 6ebc5851e6..5d8331cfcf 100644
--- a/src/calibre/gui2/metadata/basic_widgets.py
+++ b/src/calibre/gui2/metadata/basic_widgets.py
@@ -1286,6 +1286,7 @@ class TagsEdit(EditWithComplete, ToMetadataMixin):  # {{{
 
     def __init__(self, parent):
         EditWithComplete.__init__(self, parent)
+        self.lineEdit().setMaxLength(65536)  # see https://bugs.launchpad.net/bugs/1569388
         self.books_to_refresh = set([])
         self.setToolTip(self.TOOLTIP)
         self.setWhatsThis(self.TOOLTIP)