diff --git a/src/calibre/gui2/dialogs/quickview.py b/src/calibre/gui2/dialogs/quickview.py
index 92e9ffb43f..5481c4b635 100644
--- a/src/calibre/gui2/dialogs/quickview.py
+++ b/src/calibre/gui2/dialogs/quickview.py
@@ -466,13 +466,15 @@ class Quickview(QDialog, Ui_Quickview):
         Given a cell in the library view, display the information. This method
         converts the index into the lookup key
         '''
-        if self.lock_qv.isChecked():
+        if self.lock_qv.isChecked() or not idx.isValid():
             return
 
         try:
             self.current_column = (
-                self.view.column_map.index('authors') if self.current_column is None and self.view.column_map[idx.column()] == 'title'
-                else idx.column())
+                self.view.column_map.index('authors')
+                    if self.current_column is None
+                       and self.view.column_map[idx.column()] == 'title'
+                    else idx.column())
             key = self.view.column_map[self.current_column]
             book_id = self.view.model().id(idx.row())
             if self.current_book_id == book_id and self.current_key == key: