diff --git a/src/calibre/gui2/preferences/look_feel.py b/src/calibre/gui2/preferences/look_feel.py
index 064df049c2..1e32b78402 100644
--- a/src/calibre/gui2/preferences/look_feel.py
+++ b/src/calibre/gui2/preferences/look_feel.py
@@ -127,7 +127,7 @@ class IdLinksRuleEdit(Dialog):
         self.l = l = QFormLayout(self)
         l.setFieldGrowthPolicy(l.AllNonFixedFieldsGrow)
         l.addRow(QLabel(_(
-            'The key of the identifier, for example, in isbn:XXX, the key is ISBN')))
+            'The key of the identifier, for example, in isbn:XXX, the key is "isbn"')))
         self.key = k = QLineEdit(self)
         l.addRow(_('&Key:'), k)
         l.addRow(QLabel(_(