diff --git a/pylib/anki/collection.py b/pylib/anki/collection.py
index 1b47dbc10..77eab8716 100644
--- a/pylib/anki/collection.py
+++ b/pylib/anki/collection.py
@@ -379,16 +379,6 @@ class Collection:
     def cardCount(self) -> Any:
         return self.db.scalar("select count() from cards")
 
-    def card_count_from_did(self, did: int, count_subdecks: bool = False) -> Any:
-        dids: List[int] = [did]
-        if count_subdecks:
-            dids += [r[1] for r in self.decks.children(did)]
-        count = self.db.scalar(
-            "select count() from cards where did in {0} or "
-            "odid in {0}".format(ids2str(dids))
-        )
-        return count
-
     def remove_cards_and_orphaned_notes(self, card_ids: Sequence[int]):
         "You probably want .remove_notes_by_card() instead."
         self.backend.remove_cards(card_ids=card_ids)
diff --git a/pylib/anki/decks.py b/pylib/anki/decks.py
index 675da7c21..2c0132b5a 100644
--- a/pylib/anki/decks.py
+++ b/pylib/anki/decks.py
@@ -210,6 +210,16 @@ class DeckManager:
     def count(self) -> int:
         return len(self.all_names_and_ids())
 
+    def card_count(self, did: int, include_subdecks: bool) -> Any:
+        dids: List[int] = [did]
+        if include_subdecks:
+            dids += [r[1] for r in self.children(did)]
+        count = self.col.db.scalar(
+            "select count() from cards where did in {0} or "
+            "odid in {0}".format(ids2str(dids))
+        )
+        return count
+
     def get(self, did: Union[int, str], default: bool = True) -> Optional[Deck]:
         if not did:
             if default:
diff --git a/qt/aqt/deckbrowser.py b/qt/aqt/deckbrowser.py
index eb3a3adcf..24f0f9df0 100644
--- a/qt/aqt/deckbrowser.py
+++ b/qt/aqt/deckbrowser.py
@@ -277,12 +277,11 @@ class DeckBrowser:
     def _delete(self, did: int):
         self.mw.checkpoint(tr(TR.DECKS_DELETE_DECK))
         deck = self.mw.col.decks.get(did)
+        extra = None
         if not deck["dyn"]:
-            count = self.mw.col.card_count_from_did(did, count_subdecks=True)
+            count = self.mw.col.decks.card_count(did, include_subdecks=True)
             if count:
                 extra = tr(TR.DECKS_IT_HAS_CARD, count=count)
-            else:
-                extra = None
         if (
             deck["dyn"]
             or not extra