diff --git a/ankiqt/ui/cardlist.py b/ankiqt/ui/cardlist.py
index 7af3f1d34..0f130db09 100644
--- a/ankiqt/ui/cardlist.py
+++ b/ankiqt/ui/cardlist.py
@@ -431,7 +431,7 @@ class EditDeck(QMainWindow):
         elif idx == 1:
             self.dialog.filterEdit.setText("tag:none")
         else:
-            self.dialog.filterEdit.setText("tag:" + self.alltags[idx-2])
+            self.dialog.filterEdit.setText("tag:" + self.alltags[idx-2].lower())
         self.showFilterNow()
         self.dialog.tagList.setCurrentIndex(0)