diff --git a/src/calibre/gui2/actions/add.py b/src/calibre/gui2/actions/add.py
index 29d938ffb0..97f23c3e5f 100644
--- a/src/calibre/gui2/actions/add.py
+++ b/src/calibre/gui2/actions/add.py
@@ -295,7 +295,7 @@ class AddAction(InterfaceAction):
 
     def add_recursive_question(self):
         single =  question_dialog(self.gui, _('Multi-file books?'), _(
-            'Assume all e-book files in a directory are the same book in different formats?'))
+            'Assume all e-book files in a single directory are the same book in different formats?'))
         self.add_recursive(single)
 
     def add_empty(self, *args):