diff --git a/pylib/anki/cards.py b/pylib/anki/cards.py
index 703cf13fb..4e04bf453 100644
--- a/pylib/anki/cards.py
+++ b/pylib/anki/cards.py
@@ -37,6 +37,8 @@ class Card:
     ord: int
     nid: anki.notes.NoteID
     id: CardID
+    did: anki.decks.DeckID
+    odid: anki.decks.DeckID
 
     def __init__(
         self, col: anki.collection.Collection, id: Optional[CardID] = None
@@ -62,7 +64,7 @@ class Card:
         self._note = None
         self.id = CardID(c.id)
         self.nid = anki.notes.NoteID(c.note_id)
-        self.did = c.deck_id
+        self.did = anki.decks.DeckID(c.deck_id)
         self.ord = c.template_idx
         self.mod = c.mtime_secs
         self.usn = c.usn
@@ -75,7 +77,7 @@ class Card:
         self.lapses = c.lapses
         self.left = c.remaining_steps
         self.odue = c.original_due
-        self.odid = c.original_deck_id
+        self.odid = anki.decks.DeckID(c.original_deck_id)
         self.flags = c.flags
         self.data = c.data
 
@@ -163,7 +165,7 @@ class Card:
     def startTimer(self) -> None:
         self.timerStarted = time.time()
 
-    def currentDeckID(self) -> int:
+    def currentDeckID(self) -> anki.decks.DeckID:
         return anki.decks.DeckID(self.odid or self.did)
 
     def timeLimit(self) -> int:
diff --git a/pylib/anki/collection.py b/pylib/anki/collection.py
index bf9d31519..761d66e65 100644
--- a/pylib/anki/collection.py
+++ b/pylib/anki/collection.py
@@ -38,7 +38,7 @@ from anki.cards import Card, CardID
 from anki.config import Config, ConfigManager
 from anki.consts import *
 from anki.dbproxy import DBProxy
-from anki.decks import DeckManager
+from anki.decks import DeckID, DeckManager
 from anki.errors import AnkiError, DBError
 from anki.lang import TR, FormatTimeSpan
 from anki.media import MediaManager, media_paths_from_col_path
@@ -370,7 +370,7 @@ class Collection:
     def new_note(self, notetype: NoteType) -> Note:
         return Note(self, notetype)
 
-    def add_note(self, note: Note, deck_id: int) -> OpChanges:
+    def add_note(self, note: Note, deck_id: DeckID) -> OpChanges:
         out = self._backend.add_note(note=note._to_backend_note(), deck_id=deck_id)
         note.id = NoteID(out.note_id)
         return out.changes
@@ -400,21 +400,23 @@ class Collection:
         if card := current_review_card:
             home_deck = card.currentDeckID()
         else:
-            home_deck = 0
+            home_deck = DeckID(0)
 
         return self._backend.defaults_for_adding(
             home_deck_of_current_review_card=home_deck,
         )
 
-    def default_deck_for_notetype(self, notetype_id: NoteID) -> Optional[int]:
+    def default_deck_for_notetype(self, notetype_id: NoteID) -> Optional[DeckID]:
         """If 'change deck depending on notetype' is enabled in the preferences,
         return the last deck used with the provided notetype, if any.."""
         if self.get_config_bool(Config.Bool.ADDING_DEFAULTS_TO_CURRENT_DECK):
             return None
 
         return (
-            self._backend.default_deck_for_notetype(
-                ntid=notetype_id,
+            DeckID(
+                self._backend.default_deck_for_notetype(
+                    ntid=notetype_id,
+                )
             )
             or None
         )
diff --git a/pylib/anki/decks.py b/pylib/anki/decks.py
index 7bc8dd37f..7dde55020 100644
--- a/pylib/anki/decks.py
+++ b/pylib/anki/decks.py
@@ -31,7 +31,7 @@ DeckDict = Dict[str, Any]
 DeckConfigDict = Dict[str, Any]
 
 DeckID = NewType("DeckID", int)
-default_deck_id = 1
+default_deck_id = DeckID(1)
 default_deck_conf_id = 1
 
 
@@ -45,7 +45,7 @@ class DecksDictProxy:
 
     def __getitem__(self, item: Any) -> Any:
         self._warn()
-        return self._col.decks.get(int(item))
+        return self._col.decks.get(DeckID(int(item)))
 
     def __setitem__(self, key: Any, val: Any) -> None:
         self._warn()
@@ -124,7 +124,7 @@ class DeckManager:
         name: str,
         create: bool = True,
         type: int = 0,
-    ) -> Optional[int]:
+    ) -> Optional[DeckID]:
         "Add a deck with NAME. Reuse deck if already exists. Return id as int."
         id = self.id_for_name(name)
         if id:
@@ -135,17 +135,17 @@ class DeckManager:
         deck = self.new_deck_legacy(bool(type))
         deck["name"] = name
         out = self.add_deck_legacy(deck)
-        return out.id
+        return DeckID(out.id)
 
     @legacy_func(sub="remove")
-    def rem(self, did: int, cardsToo: bool = True, childrenToo: bool = True) -> None:
+    def rem(self, did: DeckID, cardsToo: bool = True, childrenToo: bool = True) -> None:
         "Remove the deck. If cardsToo, delete any cards inside."
         if isinstance(did, str):
             did = int(did)
         assert cardsToo and childrenToo
         self.remove([did])
 
-    def remove(self, dids: Sequence[int]) -> OpChangesWithCount:
+    def remove(self, dids: Sequence[DeckID]) -> OpChangesWithCount:
         return self.col._backend.remove_decks(dids)
 
     def all_names_and_ids(
@@ -156,20 +156,20 @@ class DeckManager:
             skip_empty_default=skip_empty_default, include_filtered=include_filtered
         )
 
-    def id_for_name(self, name: str) -> Optional[int]:
+    def id_for_name(self, name: str) -> Optional[DeckID]:
         try:
-            return self.col._backend.get_deck_id_by_name(name)
+            return DeckID(self.col._backend.get_deck_id_by_name(name))
         except NotFoundError:
             return None
 
-    def get_legacy(self, did: int) -> Optional[DeckDict]:
+    def get_legacy(self, did: DeckID) -> Optional[DeckDict]:
         try:
             return from_json_bytes(self.col._backend.get_deck_legacy(did))
         except NotFoundError:
             return None
 
-    def have(self, id: int) -> bool:
-        return not self.get_legacy(int(id))
+    def have(self, id: DeckID) -> bool:
+        return not self.get_legacy(id)
 
     def get_all_legacy(self) -> List[DeckDict]:
         return list(from_json_bytes(self.col._backend.get_all_decks_legacy()).values())
@@ -191,7 +191,7 @@ class DeckManager:
 
     @classmethod
     def find_deck_in_tree(
-        cls, node: DeckTreeNode, deck_id: int
+        cls, node: DeckTreeNode, deck_id: DeckID
     ) -> Optional[DeckTreeNode]:
         if node.deck_id == deck_id:
             return node
@@ -218,12 +218,12 @@ class DeckManager:
             )
         ]
 
-    def collapse(self, did: int) -> None:
+    def collapse(self, did: DeckID) -> None:
         deck = self.get(did)
         deck["collapsed"] = not deck["collapsed"]
         self.save(deck)
 
-    def collapseBrowser(self, did: int) -> None:
+    def collapseBrowser(self, did: DeckID) -> None:
         deck = self.get(did)
         collapsed = deck.get("browserCollapsed", False)
         deck["browserCollapsed"] = not collapsed
@@ -233,7 +233,7 @@ class DeckManager:
         return len(self.all_names_and_ids())
 
     def card_count(
-        self, dids: Union[int, Iterable[int]], include_subdecks: bool
+        self, dids: Union[DeckID, Iterable[DeckID]], include_subdecks: bool
     ) -> Any:
         if isinstance(dids, int):
             dids = {dids}
@@ -247,13 +247,13 @@ class DeckManager:
         )
         return count
 
-    def get(self, did: Union[int, str], default: bool = True) -> Optional[DeckDict]:
+    def get(self, did: Union[DeckID, str], default: bool = True) -> Optional[DeckDict]:
         if not did:
             if default:
                 return self.get_legacy(default_deck_id)
             else:
                 return None
-        id = int(did)
+        id = DeckID(int(did))
         deck = self.get_legacy(id)
         if deck:
             return deck
@@ -297,7 +297,9 @@ class DeckManager:
 
     # legacy
     def renameForDragAndDrop(
-        self, draggedDeckDid: Union[int, str], ontoDeckDid: Optional[Union[int, str]]
+        self,
+        draggedDeckDid: Union[DeckID, str],
+        ontoDeckDid: Optional[Union[DeckID, str]],
     ) -> None:
         if not ontoDeckDid:
             onto = 0
@@ -312,7 +314,7 @@ class DeckManager:
         "A list of all deck config."
         return list(from_json_bytes(self.col._backend.all_deck_config_legacy()))
 
-    def confForDid(self, did: int) -> DeckConfigDict:
+    def confForDid(self, did: DeckID) -> DeckConfigDict:
         deck = self.get(did, default=False)
         assert deck
         if "conf" in deck:
@@ -370,7 +372,7 @@ class DeckManager:
         grp["conf"] = id
         self.save(grp)
 
-    def didsForConf(self, conf: DeckConfigDict) -> List[int]:
+    def didsForConf(self, conf: DeckConfigDict) -> List[DeckID]:
         dids = []
         for deck in self.all():
             if "conf" in deck and deck["conf"] == conf["id"]:
@@ -397,19 +399,19 @@ class DeckManager:
     # Deck utils
     #############################################################
 
-    def name(self, did: int, default: bool = False) -> str:
+    def name(self, did: DeckID, default: bool = False) -> str:
         deck = self.get(did, default=default)
         if deck:
             return deck["name"]
         return self.col.tr(TR.DECKS_NO_DECK)
 
-    def name_if_exists(self, did: int) -> Optional[str]:
+    def name_if_exists(self, did: DeckID) -> Optional[str]:
         deck = self.get(did, default=False)
         if deck:
             return deck["name"]
         return None
 
-    def setDeck(self, cids: List[CardID], did: int) -> None:
+    def setDeck(self, cids: List[CardID], did: DeckID) -> None:
         self.col.db.execute(
             f"update cards set did=?,usn=?,mod=? where id in {ids2str(cids)}",
             did,
@@ -417,7 +419,7 @@ class DeckManager:
             intTime(),
         )
 
-    def cids(self, did: int, children: bool = False) -> List[CardID]:
+    def cids(self, did: DeckID, children: bool = False) -> List[CardID]:
         if not children:
             return self.col.db.list("select id from cards where did=?", did)
         dids = [did]
@@ -425,13 +427,13 @@ class DeckManager:
             dids.append(id)
         return self.col.db.list(f"select id from cards where did in {ids2str(dids)}")
 
-    def for_card_ids(self, cids: List[CardID]) -> List[int]:
+    def for_card_ids(self, cids: List[CardID]) -> List[DeckID]:
         return self.col.db.list(f"select did from cards where id in {ids2str(cids)}")
 
     # Deck selection
     #############################################################
 
-    def active(self) -> List[int]:
+    def active(self) -> List[DeckID]:
         "The currrently active dids."
         return self.col.get_config("activeDecks", [1])
 
@@ -442,10 +444,9 @@ class DeckManager:
     def current(self) -> DeckDict:
         return self.get(self.selected())
 
-    def select(self, did: int) -> None:
+    def select(self, did: DeckID) -> None:
         "Select a new branch."
         # make sure arg is an int
-        did = int(did)
         current = self.selected()
         active = self.deck_and_child_ids(did)
         if current != did or active != self.active():
@@ -486,29 +487,31 @@ class DeckManager:
     def key(cls, deck: DeckDict) -> List[str]:
         return cls.path(deck["name"])
 
-    def children(self, did: int) -> List[Tuple[str, int]]:
+    def children(self, did: DeckID) -> List[Tuple[str, DeckID]]:
         "All children of did, as (name, id)."
         name = self.get(did)["name"]
         actv = []
         for g in self.all_names_and_ids():
             if g.name.startswith(f"{name}::"):
-                actv.append((g.name, g.id))
+                actv.append((g.name, DeckID(g.id)))
         return actv
 
-    def child_ids(self, parent_name: str) -> Iterable[int]:
+    def child_ids(self, parent_name: str) -> Iterable[DeckID]:
         prefix = f"{parent_name}::"
-        return (d.id for d in self.all_names_and_ids() if d.name.startswith(prefix))
+        return (
+            DeckID(d.id) for d in self.all_names_and_ids() if d.name.startswith(prefix)
+        )
 
-    def deck_and_child_ids(self, deck_id: int) -> List[int]:
+    def deck_and_child_ids(self, deck_id: DeckID) -> List[DeckID]:
         parent_name = self.get_legacy(deck_id)["name"]
         out = [deck_id]
         out.extend(self.child_ids(parent_name))
         return out
 
-    childMapNode = Dict[int, Any]
+    childMapNode = Dict[DeckID, Any]
     # Change to Dict[int, "DeckManager.childMapNode"] when MyPy allow recursive type
 
-    def childDids(self, did: int, childMap: DeckManager.childMapNode) -> List:
+    def childDids(self, did: DeckID, childMap: DeckManager.childMapNode) -> List:
         def gather(node: DeckManager.childMapNode, arr: List) -> None:
             for did, child in node.items():
                 arr.append(did)
@@ -536,7 +539,7 @@ class DeckManager:
         return childMap
 
     def parents(
-        self, did: int, nameMap: Optional[Dict[str, DeckDict]] = None
+        self, did: DeckID, nameMap: Optional[Dict[str, DeckDict]] = None
     ) -> List[DeckDict]:
         "All parents of did."
         # get parent and grandparent names
@@ -578,14 +581,14 @@ class DeckManager:
     # Dynamic decks
     ##########################################################################
 
-    def new_filtered(self, name: str) -> int:
+    def new_filtered(self, name: str) -> DeckID:
         "Return a new dynamic deck and set it as the current deck."
         did = self.id(name, type=default_deck_conf_id)
         self.select(did)
         return did
 
     # 1 for dyn, 0 for standard
-    def isDyn(self, did: Union[int, str]) -> int:
+    def isDyn(self, did: Union[DeckID, str]) -> int:
         return self.get(did)["dyn"]
 
     # legacy
diff --git a/pylib/anki/exporting.py b/pylib/anki/exporting.py
index 1a559c448..f169dfb91 100644
--- a/pylib/anki/exporting.py
+++ b/pylib/anki/exporting.py
@@ -14,6 +14,7 @@ from zipfile import ZipFile
 from anki import hooks
 from anki.cards import CardID
 from anki.collection import Collection
+from anki.decks import DeckID
 from anki.lang import TR
 from anki.utils import ids2str, namedtmp, splitFields, stripHTML
 
@@ -28,7 +29,7 @@ class Exporter:
     def __init__(
         self,
         col: Collection,
-        did: Optional[int] = None,
+        did: Optional[DeckID] = None,
         cids: Optional[List[CardID]] = None,
     ) -> None:
         self.col = col.weakref()
@@ -185,7 +186,7 @@ class AnkiExporter(Exporter):
     def key(col: Collection) -> str:
         return col.tr(TR.EXPORTING_ANKI_20_DECK)
 
-    def deckIds(self) -> List[int]:
+    def deckIds(self) -> List[DeckID]:
         if self.cids:
             return self.col.decks.for_card_ids(self.cids)
         elif self.did:
diff --git a/pylib/anki/importing/anki2.py b/pylib/anki/importing/anki2.py
index 15eb3b606..5cd5824d9 100644
--- a/pylib/anki/importing/anki2.py
+++ b/pylib/anki/importing/anki2.py
@@ -8,7 +8,7 @@ from typing import Any, Dict, List, Optional, Tuple
 from anki.cards import CardID
 from anki.collection import Collection
 from anki.consts import *
-from anki.decks import DeckManager
+from anki.decks import DeckID, DeckManager
 from anki.importing.base import Importer
 from anki.lang import TR
 from anki.notes import NoteID
@@ -31,7 +31,7 @@ class Anki2Importer(Importer):
         super().__init__(col, file)
 
         # set later, defined here for typechecking
-        self._decks: Dict[int, int] = {}
+        self._decks: Dict[DeckID, DeckID] = {}
         self.source_needs_upgrade = False
 
     def run(self, media: None = None) -> None:
@@ -256,7 +256,7 @@ class Anki2Importer(Importer):
     # Decks
     ######################################################################
 
-    def _did(self, did: int) -> Any:
+    def _did(self, did: DeckID) -> Any:
         "Given did in src col, return local id."
         # already converted?
         if did in self._decks:
diff --git a/pylib/anki/scheduler/base.py b/pylib/anki/scheduler/base.py
index e61bae378..6c9e3ea8d 100644
--- a/pylib/anki/scheduler/base.py
+++ b/pylib/anki/scheduler/base.py
@@ -91,10 +91,10 @@ select id from cards where did in %s and queue = {QUEUE_TYPE_REV} and due <= ? l
     # Filtered deck handling
     ##########################################################################
 
-    def rebuild_filtered_deck(self, deck_id: int) -> OpChangesWithCount:
+    def rebuild_filtered_deck(self, deck_id: DeckID) -> OpChangesWithCount:
         return self.col._backend.rebuild_filtered_deck(deck_id)
 
-    def empty_filtered_deck(self, deck_id: int) -> OpChanges:
+    def empty_filtered_deck(self, deck_id: DeckID) -> OpChanges:
         return self.col._backend.empty_filtered_deck(deck_id)
 
     def get_or_create_filtered_deck(self, deck_id: DeckID) -> FilteredDeckForUpdate:
@@ -199,10 +199,10 @@ select id from cards where did in %s and queue = {QUEUE_TYPE_REV} and due <= ? l
             shift_existing=shift_existing,
         )
 
-    def randomizeCards(self, did: int) -> None:
+    def randomizeCards(self, did: DeckID) -> None:
         self.col._backend.sort_deck(deck_id=did, randomize=True)
 
-    def orderCards(self, did: int) -> None:
+    def orderCards(self, did: DeckID) -> None:
         self.col._backend.sort_deck(deck_id=did, randomize=False)
 
     def resortConf(self, conf: DeckConfigDict) -> None:
@@ -213,7 +213,7 @@ select id from cards where did in %s and queue = {QUEUE_TYPE_REV} and due <= ? l
                 self.orderCards(did)
 
     # for post-import
-    def maybeRandomizeDeck(self, did: Optional[int] = None) -> None:
+    def maybeRandomizeDeck(self, did: Optional[DeckID] = None) -> None:
         if not did:
             did = self.col.decks.selected()
         conf = self.col.decks.confForDid(did)
diff --git a/pylib/anki/scheduler/legacy.py b/pylib/anki/scheduler/legacy.py
index 6eb2e1023..7aafc0192 100644
--- a/pylib/anki/scheduler/legacy.py
+++ b/pylib/anki/scheduler/legacy.py
@@ -5,7 +5,7 @@ from typing import List, Optional, Tuple
 
 from anki.cards import Card, CardID
 from anki.consts import CARD_TYPE_RELEARNING, QUEUE_TYPE_DAY_LEARN_RELEARN
-from anki.decks import DeckConfigDict
+from anki.decks import DeckConfigDict, DeckID
 from anki.notes import NoteID
 from anki.scheduler.base import SchedulerBase, UnburyCurrentDeck
 from anki.utils import from_json_bytes, ids2str
@@ -49,7 +49,7 @@ class SchedulerBaseWithLegacy(SchedulerBase):
         print("_nextDueMsg() is obsolete")
         return ""
 
-    def rebuildDyn(self, did: Optional[int] = None) -> Optional[int]:
+    def rebuildDyn(self, did: Optional[DeckID] = None) -> Optional[int]:
         did = did or self.col.decks.selected()
         count = self.rebuild_filtered_deck(did).count or None
         if not count:
@@ -58,7 +58,7 @@ class SchedulerBaseWithLegacy(SchedulerBase):
         self.col.decks.select(did)
         return count
 
-    def emptyDyn(self, did: Optional[int], lim: Optional[str] = None) -> None:
+    def emptyDyn(self, did: Optional[DeckID], lim: Optional[str] = None) -> None:
         if lim is None:
             self.empty_filtered_deck(did)
             return
@@ -86,7 +86,7 @@ due = (case when odue>0 then odue else due end), odue = 0, odid = 0, usn = ? whe
     # used by v2 scheduler and some add-ons
     def update_stats(
         self,
-        deck_id: int,
+        deck_id: DeckID,
         new_delta: int = 0,
         review_delta: int = 0,
         milliseconds_delta: int = 0,
diff --git a/pylib/anki/scheduler/v1.py b/pylib/anki/scheduler/v1.py
index 6aec92fab..3d1c3c39c 100644
--- a/pylib/anki/scheduler/v1.py
+++ b/pylib/anki/scheduler/v1.py
@@ -12,6 +12,7 @@ import anki
 from anki import hooks
 from anki.cards import Card
 from anki.consts import *
+from anki.decks import DeckID
 from anki.utils import ids2str, intTime
 
 from .v2 import QueueConfig
@@ -299,7 +300,7 @@ limit %d"""
         if card.odid:
             card.did = card.odid
             card.odue = 0
-            card.odid = 0
+            card.odid = DeckID(0)
             # if rescheduling is off, it needs to be set back to a new card
             if not resched and not lapse:
                 card.queue = card.type = CARD_TYPE_NEW
@@ -401,7 +402,7 @@ where queue in ({QUEUE_TYPE_LRN},{QUEUE_TYPE_DAY_LEARN_RELEARN}) and type = {CAR
             )
         )
 
-    def _lrnForDeck(self, did: int) -> int:
+    def _lrnForDeck(self, did: DeckID) -> int:
         cnt = (
             self.col.db.scalar(
                 f"""
@@ -426,7 +427,7 @@ and due <= ? limit ?)""",
     # Reviews
     ##########################################################################
 
-    def _deckRevLimit(self, did: int) -> int:
+    def _deckRevLimit(self, did: DeckID) -> int:
         return self._deckNewLimit(did, self._deckRevLimitSingle)
 
     def _resetRev(self) -> None:
@@ -541,7 +542,7 @@ did = ? and queue = {QUEUE_TYPE_REV} and due <= ? limit ?""",
             card.due = card.odue
         if card.odid:
             card.did = card.odid
-            card.odid = 0
+            card.odid = DeckID(0)
             card.odue = 0
 
     # Interval management
@@ -617,7 +618,8 @@ did = ? and queue = {QUEUE_TYPE_REV} and due <= ? limit ?""",
                     card.due = card.odue
                 if card.odid:
                     card.did = card.odid
-                card.odue = card.odid = 0
+                card.odue = 0
+                card.odid = DeckID(0)
                 card.queue = QUEUE_TYPE_SUSPENDED
             # notify UI
             hooks.card_did_leech(card)
diff --git a/pylib/anki/scheduler/v2.py b/pylib/anki/scheduler/v2.py
index a6d1aa8c5..31fcd0f67 100644
--- a/pylib/anki/scheduler/v2.py
+++ b/pylib/anki/scheduler/v2.py
@@ -13,7 +13,7 @@ import anki._backend.backend_pb2 as _pb
 from anki import hooks
 from anki.cards import Card, CardID
 from anki.consts import *
-from anki.decks import DeckConfigDict, DeckDict
+from anki.decks import DeckConfigDict, DeckDict, DeckID
 from anki.lang import FormatTimeSpan
 from anki.scheduler.legacy import SchedulerBaseWithLegacy
 from anki.utils import ids2str, intTime
@@ -75,7 +75,9 @@ class Scheduler(SchedulerBaseWithLegacy):
 
     def _reset_counts(self) -> None:
         tree = self.deck_due_tree(self.col.decks.selected())
-        node = self.col.decks.find_deck_in_tree(tree, int(self.col.conf["curDeck"]))
+        node = self.col.decks.find_deck_in_tree(
+            tree, DeckID(int(self.col.conf["curDeck"]))
+        )
         if not node:
             # current deck points to a missing deck
             self.newCount = 0
@@ -210,7 +212,7 @@ class Scheduler(SchedulerBaseWithLegacy):
             return None
 
     def _deckNewLimit(
-        self, did: int, fn: Optional[Callable[[DeckDict], int]] = None
+        self, did: DeckID, fn: Optional[Callable[[DeckDict], int]] = None
     ) -> int:
         if not fn:
             fn = self._deckNewLimitSingle
@@ -225,7 +227,7 @@ class Scheduler(SchedulerBaseWithLegacy):
                 lim = min(rem, lim)
         return lim
 
-    def _newForDeck(self, did: int, lim: int) -> int:
+    def _newForDeck(self, did: DeckID, lim: int) -> int:
         "New count for a single deck."
         if not lim:
             return 0
@@ -788,7 +790,7 @@ limit ?"""
         if card.odid:
             card.did = card.odid
             card.odue = 0
-            card.odid = 0
+            card.odid = DeckID(0)
 
     def _restorePreviewCard(self, card: Card) -> None:
         assert card.odid
diff --git a/pylib/anki/tags.py b/pylib/anki/tags.py
index fa57d7502..036fb4efa 100644
--- a/pylib/anki/tags.py
+++ b/pylib/anki/tags.py
@@ -19,6 +19,7 @@ import anki  # pylint: disable=unused-import
 import anki._backend.backend_pb2 as _pb
 import anki.collection
 from anki.collection import OpChangesWithCount
+from anki.decks import DeckID
 from anki.notes import NoteID
 from anki.utils import ids2str
 
@@ -49,7 +50,7 @@ class TagManager:
     def clear_unused_tags(self) -> OpChangesWithCount:
         return self.col._backend.clear_unused_tags()
 
-    def byDeck(self, did: int, children: bool = False) -> List[str]:
+    def byDeck(self, did: DeckID, children: bool = False) -> List[str]:
         basequery = "select n.tags from cards c, notes n WHERE c.nid = n.id"
         if not children:
             query = f"{basequery} AND c.did=?"
diff --git a/qt/aqt/addcards.py b/qt/aqt/addcards.py
index fc57e8831..66f13c037 100644
--- a/qt/aqt/addcards.py
+++ b/qt/aqt/addcards.py
@@ -8,6 +8,7 @@ import aqt.editor
 import aqt.forms
 from anki.collection import OpChanges, SearchNode
 from anki.consts import MODEL_CLOZE
+from anki.decks import DeckID
 from anki.notes import DuplicateOrEmptyResult, Note, NoteID
 from anki.utils import htmlToTextLine, isMac
 from aqt import AnkiQt, gui_hooks
@@ -69,7 +70,7 @@ class AddCards(QDialog):
             on_notetype_changed=self.on_notetype_change,
         )
         self.deck_chooser = aqt.deckchooser.DeckChooser(
-            self.mw, self.form.deckArea, starting_deck_id=defaults.deck_id
+            self.mw, self.form.deckArea, starting_deck_id=DeckID(defaults.deck_id)
         )
 
     def helpRequested(self) -> None:
diff --git a/qt/aqt/deckbrowser.py b/qt/aqt/deckbrowser.py
index ddf297189..ecb326d00 100644
--- a/qt/aqt/deckbrowser.py
+++ b/qt/aqt/deckbrowser.py
@@ -40,7 +40,7 @@ class DeckBrowserContent:
 
 @dataclass
 class RenderDeckNodeContext:
-    current_deck_id: int
+    current_deck_id: DeckID
 
 
 class DeckBrowser:
@@ -101,7 +101,7 @@ class DeckBrowser:
             source, target = arg.split(",")
             self._handle_drag_and_drop(DeckID(int(source)), DeckID(int(target or 0)))
         elif cmd == "collapse":
-            self._collapse(int(arg))
+            self._collapse(DeckID(int(arg)))
         elif cmd == "v2upgrade":
             self._confirm_upgrade()
         elif cmd == "v2upgradeinfo":
@@ -112,7 +112,7 @@ class DeckBrowser:
         return False
 
     def _selDeck(self, did: str) -> None:
-        self.mw.col.decks.select(int(did))
+        self.mw.col.decks.select(DeckID(int(did)))
         self.mw.onOverview()
 
     # HTML generation
@@ -255,13 +255,13 @@ class DeckBrowser:
         a = m.addAction(tr(TR.ACTIONS_OPTIONS))
         qconnect(a.triggered, lambda b, did=did: self._options(DeckID(int(did))))
         a = m.addAction(tr(TR.ACTIONS_EXPORT))
-        qconnect(a.triggered, lambda b, did=did: self._export(int(did)))
+        qconnect(a.triggered, lambda b, did=did: self._export(DeckID(int(did))))
         a = m.addAction(tr(TR.ACTIONS_DELETE))
         qconnect(a.triggered, lambda b, did=did: self._delete(DeckID(int(did))))
         gui_hooks.deck_browser_will_show_options_menu(m, int(did))
         m.exec_(QCursor.pos())
 
-    def _export(self, did: int) -> None:
+    def _export(self, did: DeckID) -> None:
         self.mw.onExport(did=did)
 
     def _rename(self, did: DeckID) -> None:
@@ -279,7 +279,7 @@ class DeckBrowser:
         self.mw.col.decks.select(did)
         self.mw.onDeckConf()
 
-    def _collapse(self, did: int) -> None:
+    def _collapse(self, did: DeckID) -> None:
         self.mw.col.decks.collapse(did)
         node = self.mw.col.decks.find_deck_in_tree(self._dueTree, did)
         if node:
diff --git a/qt/aqt/deckchooser.py b/qt/aqt/deckchooser.py
index a6fc08da8..81ddc5ba8 100644
--- a/qt/aqt/deckchooser.py
+++ b/qt/aqt/deckchooser.py
@@ -3,7 +3,7 @@
 
 from typing import Optional
 
-from anki.decks import default_deck_id
+from anki.decks import DeckID, default_deck_id
 from aqt import AnkiQt
 from aqt.qt import *
 from aqt.utils import TR, HelpPage, shortcut, tr
@@ -15,17 +15,17 @@ class DeckChooser(QHBoxLayout):
         mw: AnkiQt,
         widget: QWidget,
         label: bool = True,
-        starting_deck_id: Optional[int] = None,
+        starting_deck_id: Optional[DeckID] = None,
     ) -> None:
         QHBoxLayout.__init__(self)
         self._widget = widget  # type: ignore
         self.mw = mw
         self._setup_ui(show_label=label)
 
-        self._selected_deck_id = 0
+        self._selected_deck_id = DeckID(0)
         # default to current deck if starting id not provided
         if starting_deck_id is None:
-            starting_deck_id = self.mw.col.get_config("curDeck", default=1) or 1
+            starting_deck_id = DeckID(self.mw.col.get_config("curDeck", default=1) or 1)
         self.selected_deck_id = starting_deck_id
 
     def _setup_ui(self, show_label: bool) -> None:
@@ -57,13 +57,13 @@ class DeckChooser(QHBoxLayout):
         )
 
     @property
-    def selected_deck_id(self) -> int:
+    def selected_deck_id(self) -> DeckID:
         self._ensure_selected_deck_valid()
 
         return self._selected_deck_id
 
     @selected_deck_id.setter
-    def selected_deck_id(self, id: int) -> None:
+    def selected_deck_id(self, id: DeckID) -> None:
         if id != self._selected_deck_id:
             self._selected_deck_id = id
             self._ensure_selected_deck_valid()
@@ -104,7 +104,7 @@ class DeckChooser(QHBoxLayout):
     onDeckChange = choose_deck
     deckName = selected_deck_name
 
-    def selectedId(self) -> int:
+    def selectedId(self) -> DeckID:
         return self.selected_deck_id
 
     def cleanup(self) -> None:
diff --git a/qt/aqt/exporting.py b/qt/aqt/exporting.py
index bb5ec145c..45fc0a1b5 100644
--- a/qt/aqt/exporting.py
+++ b/qt/aqt/exporting.py
@@ -12,6 +12,7 @@ from typing import List, Optional
 import aqt
 from anki import hooks
 from anki.cards import CardID
+from anki.decks import DeckID
 from anki.exporting import Exporter, exporters
 from aqt.qt import *
 from aqt.utils import (
@@ -29,7 +30,7 @@ class ExportDialog(QDialog):
     def __init__(
         self,
         mw: aqt.main.AnkiQt,
-        did: Optional[int] = None,
+        did: Optional[DeckID] = None,
         cids: Optional[List[CardID]] = None,
     ):
         QDialog.__init__(self, mw, Qt.Window)
@@ -43,7 +44,7 @@ class ExportDialog(QDialog):
         self.setup(did)
         self.exec_()
 
-    def setup(self, did: Optional[int]) -> None:
+    def setup(self, did: Optional[DeckID]) -> None:
         self.exporters = exporters(self.col)
         # if a deck specified, start with .apkg type selected
         idx = 0
diff --git a/qt/aqt/main.py b/qt/aqt/main.py
index e8e8fcd59..ca67ac452 100644
--- a/qt/aqt/main.py
+++ b/qt/aqt/main.py
@@ -52,7 +52,7 @@ from anki.collection import (
     UndoResult,
     UndoStatus,
 )
-from anki.decks import DeckDict
+from anki.decks import DeckDict, DeckID
 from anki.hooks import runHook
 from anki.notes import NoteID
 from anki.sound import AVTag, SoundOrVideoTag
@@ -518,7 +518,7 @@ class AnkiQt(QMainWindow):
         except Exception as e:
             if "FileTooNew" in str(e):
                 showWarning(
-                    "This profile requires a newer version of Anki to open. Did you forget to use the Downgrade button prior to switching Anki versions?"
+                    "This profile requires a newer version of Anki to open. DeckID you forget to use the Downgrade button prior to switching Anki versions?"
                 )
             else:
                 showWarning(
@@ -1382,7 +1382,7 @@ title="%s" %s>%s</button>""" % (
 
         aqt.importing.onImport(self)
 
-    def onExport(self, did: Optional[int] = None) -> None:
+    def onExport(self, did: Optional[DeckID] = None) -> None:
         import aqt.exporting
 
         aqt.exporting.ExportDialog(self, did=did)
diff --git a/qt/aqt/note_ops.py b/qt/aqt/note_ops.py
index 042490988..6df6a028e 100644
--- a/qt/aqt/note_ops.py
+++ b/qt/aqt/note_ops.py
@@ -5,6 +5,7 @@ from __future__ import annotations
 
 from typing import Callable, Sequence
 
+from anki.decks import DeckID
 from anki.notes import Note, NoteID
 from aqt import AnkiQt
 from aqt.main import PerformOpOptionalSuccessCallback
@@ -14,7 +15,7 @@ def add_note(
     *,
     mw: AnkiQt,
     note: Note,
-    target_deck_id: int,
+    target_deck_id: DeckID,
     success: PerformOpOptionalSuccessCallback = None,
 ) -> None:
     mw.perform_op(lambda: mw.col.add_note(note, target_deck_id), success=success)
diff --git a/qt/aqt/sidebar.py b/qt/aqt/sidebar.py
index 1827da0e0..e773b28fe 100644
--- a/qt/aqt/sidebar.py
+++ b/qt/aqt/sidebar.py
@@ -976,7 +976,7 @@ class SidebarTreeView(QTreeView):
             for node in nodes:
 
                 def toggle_expand() -> Callable[[bool], None]:
-                    did = node.deck_id  # pylint: disable=cell-var-from-loop
+                    did = DeckID(node.deck_id)  # pylint: disable=cell-var-from-loop
                     return lambda _: self.mw.col.decks.collapseBrowser(did)
 
                 item = SidebarItem(
@@ -1158,7 +1158,7 @@ class SidebarTreeView(QTreeView):
     ###########################
 
     def rename_deck(self, item: SidebarItem, new_name: str) -> None:
-        deck = self.mw.col.decks.get(item.id)
+        deck = self.mw.col.decks.get(DeckID(item.id))
         if not new_name:
             return
         new_name = item.name_prefix + new_name
diff --git a/qt/aqt/studydeck.py b/qt/aqt/studydeck.py
index 6e18a3e8a..1156d662c 100644
--- a/qt/aqt/studydeck.py
+++ b/qt/aqt/studydeck.py
@@ -5,6 +5,7 @@ from typing import List, Optional
 
 import aqt
 from anki.collection import OpChangesWithID
+from anki.decks import DeckID
 from aqt import gui_hooks
 from aqt.deck_ops import add_deck_dialog
 from aqt.qt import *
@@ -167,7 +168,7 @@ class StudyDeck(QDialog):
             default = self.names[self.form.list.currentRow()]
 
         def success(out: OpChangesWithID) -> None:
-            deck = self.mw.col.decks.get(out.id)
+            deck = self.mw.col.decks.get(DeckID(out.id))
             self.name = deck["name"]
 
             # make sure we clean up reset hook when manually exiting