diff --git a/src/calibre/gui2/dialogs/check_library.py b/src/calibre/gui2/dialogs/check_library.py
index b23b807063..9ce1118b56 100644
--- a/src/calibre/gui2/dialogs/check_library.py
+++ b/src/calibre/gui2/dialogs/check_library.py
@@ -205,7 +205,7 @@ class CheckLibraryDialog(QDialog):
             _('Enter comma-separated standard file name wildcards, such as synctoy*.dat'))
         ln.setBuddy(self.name_ignores)
         h.addWidget(self.name_ignores)
-        le = QLabel(_('Extensions to ignore'))
+        le = QLabel(_('Extensions to ignore:'))
         h.addWidget(le)
         self.ext_ignores = QLineEdit()
         self.ext_ignores.setText(db.prefs.get('check_library_ignore_extensions', ''))