diff --git a/secret_loader/__init__.py b/secret_loader/__init__.py
index ba97cbf..dc459de 100644
--- a/secret_loader/__init__.py
+++ b/secret_loader/__init__.py
@@ -1,5 +1,6 @@
 import logging
 import os
+
 from frozendict import frozendict
 
 logger = logging.getLogger(__name__)
@@ -14,9 +15,9 @@ ENV_KEY_VAULT_URL = 'VAULT_URL'
 ENV_KEY_VAULT_TOKEN = 'VAULT_TOKEN'
 ENV_KEY_VAULT_MOUNT_POINT = 'VAULT_MOUNT_POINT'
 
+
 class SecretLoader:
-    """
-    Priority order:
+    """Priority order:
 
     0. Hardcoded values. This is purely for prototyping.
     1. Files pointed to by environment variables.
@@ -24,19 +25,19 @@ class SecretLoader:
     3. Vault instance if configured. Most suited for production environments.
     """
 
-    def __init__(self, env_key_prefix: str, hardcoded: dict[str,str] | None = None):
+    def __init__(self, env_key_prefix: str, hardcoded: dict[str, str] | None = None):
         assert not env_key_prefix.endswith('_')
         self.env_key_prefix = env_key_prefix
 
-        self.hardcoded: dict[str,str] = hardcoded if hardcoded is not None else {}
+        self.hardcoded: dict[str, str] = hardcoded if hardcoded is not None else {}
 
         # Setup vault
         self.vault_client = None
         if hvac:
             self.vault_client = hvac.Client(
-                    url=self._load_or_none(ENV_KEY_VAULT_URL),
-                    token=self._load_or_none(ENV_KEY_VAULT_TOKEN),
-                    vault_mount_point=self._load_or_none(ENV_KEY_VAULT_MOUNT_POINT),
+                url=self._load_or_none(ENV_KEY_VAULT_URL),
+                token=self._load_or_none(ENV_KEY_VAULT_TOKEN),
+                vault_mount_point=self._load_or_none(ENV_KEY_VAULT_MOUNT_POINT),
             )
 
     def load_or_fail(self, env_key: str) -> str:
@@ -55,7 +56,11 @@ class SecretLoader:
         return value
 
     def _load_or_none(self, env_key: str) -> str | None:
-        return self.hardcoded.get(env_key) or self._load_or_none_path_or_file(env_key) or self._load_or_none_vault(env_key)
+        return (
+            self.hardcoded.get(env_key)
+            or self._load_or_none_path_or_file(env_key)
+            or self._load_or_none_vault(env_key)
+        )
 
     def _load_or_none_path_or_file(self, env_key: str) -> str | None:
         # 1. & 2.
diff --git a/test/test_init.py b/test/test_init.py
index d76e1ed..f3cc1ad 100644
--- a/test/test_init.py
+++ b/test/test_init.py
@@ -1,6 +1,6 @@
-
 import secret_loader
 
+
 def test_init():
-    loader = secret_loader.SecretLoader('TEST', hardcoded = {'KEY': 'VALUE'})
+    loader = secret_loader.SecretLoader('TEST', hardcoded={'KEY': 'VALUE'})
     assert loader.load('KEY') == 'VALUE'