diff --git a/src/calibre/gui2/preferences/look_feel.py b/src/calibre/gui2/preferences/look_feel.py
index c58ded2e76..79dfed745c 100644
--- a/src/calibre/gui2/preferences/look_feel.py
+++ b/src/calibre/gui2/preferences/look_feel.py
@@ -69,6 +69,7 @@ class DefaultAuthorLink(QWidget):  # {{{
             c.addItem(text, data)
         l.addRow(_('Clicking on &author names should:'), c)
         self.custom_url = u = QLineEdit(self)
+        u.setPlaceholderText(_('Enter the URL'))
         c.currentIndexChanged.connect(self.current_changed)
         l.addRow(u)
         self.current_changed()