diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 74056e63..145fbad3 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -9,7 +9,7 @@ ci:
 
 repos:
   - repo: https://github.com/psf/black
-    rev: "24.4.2"
+    rev: "24.8.0"
     hooks:
       - id: black-jupyter
 
@@ -51,13 +51,13 @@ repos:
         args: [--prose-wrap=always]
 
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: "v0.5.0"
+    rev: "v0.5.6"
     hooks:
       - id: ruff
         args: ["--fix", "--show-fixes"]
 
   - repo: https://github.com/pre-commit/mirrors-mypy
-    rev: "v1.10.1"
+    rev: "v1.11.1"
     hooks:
       - id: mypy
         files: src
diff --git a/src/caustics/models/utils.py b/src/caustics/models/utils.py
index 27060b75..6626e691 100644
--- a/src/caustics/models/utils.py
+++ b/src/caustics/models/utils.py
@@ -150,7 +150,7 @@ def _init_kwargs_field_check(cls, v, info: ValidationInfo):
             field_name = info.field_name
             field = cls.model_fields[field_name]
             anno_args = typing.get_args(field.annotation)
-            if len(anno_args) == 2 and anno_args[1] == type(None):
+            if len(anno_args) == 2 and anno_args[1] is type(None):
                 # This means that the anno is optional
                 expected_type = next(
                     filter(lambda x: x is not None, typing.get_args(field.annotation))