diff --git a/src/calibre/gui2/tweak_book/widgets.py b/src/calibre/gui2/tweak_book/widgets.py
index 154ec49f7e..852f396aac 100644
--- a/src/calibre/gui2/tweak_book/widgets.py
+++ b/src/calibre/gui2/tweak_book/widgets.py
@@ -657,6 +657,7 @@ class InsertLink(Dialog):
         h.addLayout(fnl), h.setStretch(1, 1)
 
         self.tl = tl = QFormLayout()
+        tl.setFieldGrowthPolicy(tl.AllNonFixedFieldsGrow)
         self.target = t = QLineEdit(self)
         t.setPlaceholderText(_('The destination (href) for the link'))
         tl.addRow(_('&Target:'), t)