diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index c8ddcbd..730e08d 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -14,11 +14,11 @@ repos:
       - id: pyupgrade
         args: [--py37-plus, --keep-percent-format]
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.15.21
+    rev: v0.16.6
     hooks:
       - id: ruff
       - id: ruff-format
   - repo: https://github.com/pre-commit/mirrors-mypy
-    rev: 'v2.3.0'
+    rev: 'v2.3.1'
     hooks:
     -   id: mypy
diff --git a/README.md b/README.md
index ac38066..00c0f75 100644
--- a/README.md
+++ b/README.md
@@ -68,7 +68,7 @@ This simple example shows how to setup the library and retrieve all invoices:
 import os
 from easyverein import EasyvereinAPI
 
-api_key = os.getenv('EV_API_KEY', '')
+api_key = os.getenv("EV_API_KEY", "")
 
 ev_client = EasyvereinAPI(api_key)