diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 0971bc33..b816ca20 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -16,7 +16,7 @@ ci:
 repos:
   # Autoformat: Python code, syntax patterns are modernized
   - repo: https://github.com/asottile/pyupgrade
-    rev: v3.14.0
+    rev: v3.15.0
     hooks:
       - id: pyupgrade
         args:
@@ -39,7 +39,7 @@ repos:
 
   # Autoformat: Python code
   - repo: https://github.com/psf/black
-    rev: 23.9.1
+    rev: 23.10.1
     hooks:
       - id: black
 
@@ -51,7 +51,7 @@ repos:
 
   # Autoformat and linting, misc. details
   - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v4.4.0
+    rev: v4.5.0
     hooks:
       - id: end-of-file-fixer
         exclude: share/jupyterhub/static/js/admin-react.js
diff --git a/jupyterhub/user.py b/jupyterhub/user.py
index e4a38f01..0ba868a9 100644
--- a/jupyterhub/user.py
+++ b/jupyterhub/user.py
@@ -187,7 +187,7 @@ class UserDict(dict):
 
         Returns dict with counts of active/pending/ready servers
         """
-        counts = defaultdict(lambda: 0)
+        counts = defaultdict(int)
         for user in self.values():
             for spawner in user.spawners.values():
                 pending = spawner.pending