diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 88b61f7..0f7c8f3 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -3,7 +3,7 @@
 
 repos:
   - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v4.4.0
+    rev: 2c9f875913ee60ca25ce70243dc24d5b6415598c # frozen: v4.6.0
     hooks:
       - id: trailing-whitespace
       - id: end-of-file-fixer
@@ -17,23 +17,23 @@ repos:
       - id: check-added-large-files
 
   - repo: https://github.com/psf/black
-    rev: 23.3.0
+    rev: 3702ba224ecffbcec30af640c149f231d90aebdb # frozen: 24.4.2
     hooks:
       - id: black
 
   - repo: https://github.com/adamchainz/blacken-docs
-    rev: 1.13.0
+    rev: 4c97c4a0d921007af6fefae92d8447cfbf63720b # frozen: 1.18.0
     hooks:
       - id: blacken-docs
 
   - repo: https://github.com/charliermarsh/ruff-pre-commit
     # Ruff version.
-    rev: "v0.0.261"
+    rev: "1dc9eb131c2ea4816c708e4d85820d2cc8542683" # frozen: v0.5.0
     hooks:
       - id: ruff
 
   - repo: https://github.com/pre-commit/mirrors-prettier
-    rev: v2.7.1
+    rev: ffb6a759a979008c0e6dff86e39f4745a2d9eac4 # frozen: v3.1.0
     hooks:
       - id: prettier
         files: \.(html|md|yml|yaml|toml)
diff --git a/yaml2ics.py b/yaml2ics.py
index 294d0c4..59b8ed1 100644
--- a/yaml2ics.py
+++ b/yaml2ics.py
@@ -4,6 +4,7 @@
 
 CLI to convert yaml into ics.
 """
+
 import datetime
 import os
 import sys