diff --git a/pylib/anki/decks.py b/pylib/anki/decks.py
index a149adc81..e19999cea 100644
--- a/pylib/anki/decks.py
+++ b/pylib/anki/decks.py
@@ -7,6 +7,7 @@ import copy
 import json
 import operator
 import unicodedata
+import weakref
 from typing import Any, Dict, List, Optional, Set, Tuple, Union
 
 import anki  # pylint: disable=unused-import
@@ -101,7 +102,7 @@ class DeckManager:
     #############################################################
 
     def __init__(self, col: anki.storage._Collection) -> None:
-        self.col = col
+        self.col = weakref.proxy(col)
         self.decks = {}
         self.dconf = {}
 
diff --git a/pylib/anki/media.py b/pylib/anki/media.py
index 1b947cd59..96ef0e846 100644
--- a/pylib/anki/media.py
+++ b/pylib/anki/media.py
@@ -10,6 +10,7 @@ import time
 import urllib.error
 import urllib.parse
 import urllib.request
+import weakref
 from typing import Any, Callable, List, Optional, Tuple, Union
 
 import anki
@@ -42,7 +43,7 @@ class MediaManager:
     regexps = soundRegexps + imgRegexps
 
     def __init__(self, col: anki.storage._Collection, server: bool) -> None:
-        self.col = col
+        self.col = weakref.proxy(col)
         if server:
             self._dir = None
             return
diff --git a/pylib/anki/models.py b/pylib/anki/models.py
index 858604b60..d74973142 100644
--- a/pylib/anki/models.py
+++ b/pylib/anki/models.py
@@ -7,6 +7,7 @@ import copy
 import json
 import re
 import time
+import weakref
 from typing import Any, Callable, Dict, List, Optional, Tuple, Union
 
 import anki  # pylint: disable=unused-import
@@ -91,7 +92,7 @@ class ModelManager:
     #############################################################
 
     def __init__(self, col: anki.storage._Collection) -> None:
-        self.col = col
+        self.col = weakref.proxy(col)
         self.models = {}
         self.changed = False
 
diff --git a/pylib/anki/rsbackend.py b/pylib/anki/rsbackend.py
index 26d0eef66..22f9e547a 100644
--- a/pylib/anki/rsbackend.py
+++ b/pylib/anki/rsbackend.py
@@ -176,12 +176,14 @@ def proto_progress_to_native(progress: pb.Progress) -> Progress:
     else:
         assert_impossible_literal(kind)
 
+
 def _on_progress(progress_bytes: bytes) -> bool:
     progress = pb.Progress()
     progress.ParseFromString(progress_bytes)
     native_progress = proto_progress_to_native(progress)
     return hooks.bg_thread_progress_callback(True, native_progress)
 
+
 class RustBackend:
     def __init__(
         self, col_path: str, media_folder_path: str, media_db_path: str, log_path: str
diff --git a/pylib/anki/sched.py b/pylib/anki/sched.py
index e4afefce3..9c436cc0e 100644
--- a/pylib/anki/sched.py
+++ b/pylib/anki/sched.py
@@ -6,6 +6,7 @@ from __future__ import annotations
 import itertools
 import random
 import time
+import weakref
 from heapq import *
 from operator import itemgetter
 from typing import Any, Callable, Dict, List, Optional, Set, Tuple, Union
@@ -30,7 +31,7 @@ class Scheduler:
     _burySiblingsOnAnswer = True
 
     def __init__(self, col: anki.storage._Collection) -> None:
-        self.col = col
+        self.col = weakref.proxy(col)
         self.queueLimit = 50
         self.reportLimit = 1000
         self.reps = 0
diff --git a/pylib/anki/schedv2.py b/pylib/anki/schedv2.py
index 5307e8f90..88a8a10c8 100644
--- a/pylib/anki/schedv2.py
+++ b/pylib/anki/schedv2.py
@@ -7,6 +7,7 @@ import datetime
 import itertools
 import random
 import time
+import weakref
 from heapq import *
 from operator import itemgetter
 
@@ -37,7 +38,7 @@ class Scheduler:
     revCount: int
 
     def __init__(self, col: anki.storage._Collection) -> None:
-        self.col = col
+        self.col = weakref.proxy(col)
         self.queueLimit = 50
         self.reportLimit = 1000
         self.dynReportLimit = 99999
diff --git a/pylib/anki/tags.py b/pylib/anki/tags.py
index cfbb9d62e..6085fa7b5 100644
--- a/pylib/anki/tags.py
+++ b/pylib/anki/tags.py
@@ -13,6 +13,7 @@ from __future__ import annotations
 
 import json
 import re
+import weakref
 from typing import Callable, Collection, Dict, List, Optional, Tuple
 
 import anki  # pylint: disable=unused-import
@@ -26,7 +27,7 @@ class TagManager:
     #############################################################
 
     def __init__(self, col: anki.storage._Collection) -> None:
-        self.col = col
+        self.col = weakref.proxy(col)
         self.tags: Dict[str, int] = {}
 
     def load(self, json_: str) -> None: